Battery monomer, battery device, electric equipment and energy storage device

Abstract

The utility model provides a battery monomer, a battery device, electric equipment and an energy storage device, and belongs to the technical field of batteries. Each single battery comprises a shell, an electrode assembly and an electrode unit, the shell is provided with a first wall, a part of the first wall arches towards the outside of the shell to form a lug boss, and the lug boss is provided with a mounting hole in a penetrating manner. The electrode unit comprises a pole and a first limiting piece and a second limiting piece which are connected through the pole, the pole penetrates through the mounting hole, the first limiting piece and the second limiting piece are both overlapped with at least part of the first wall, the first limiting piece is arranged on the side, facing the electrode assembly, of the first wall, and the second limiting piece is arranged on the side, away from the electrode assembly, of the first wall; the side, facing the electrode assembly, of the protruding part is provided with a containing groove, and at least part of the first limiting piece is contained in the containing groove. The mounting position of the electrode unit is arched towards the outside of the shell, so that a larger mounting space can be reserved in the shell for the electrode assembly, and the energy density of the battery monomer and the endurance mileage of the electric vehicle can be improved.

Description

Technical Field

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

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. In the field of electric vehicles, the power battery, as the power source, plays an irreplaceable and crucial role. A power battery consists of several individual battery cells; however, the energy density of these individual cells needs improvement, which in turn requires increasing the driving range of electric vehicles. Utility Model Content

[0003] This application aims to at least solve one of the technical problems existing in the prior art. To this end, one object of this application is to provide a battery cell, battery device, electrical device, and energy storage device that can effectively improve the energy density of the battery cell, thereby enabling the electric vehicle using the battery cell of the embodiment of this application to also effectively improve its driving range.

[0004] An embodiment of the first aspect of this application provides a battery cell, including: a housing, an electrode assembly, and an electrode unit. The housing has a first wall, the electrode assembly is housed within the housing, and the electrode unit is disposed on the first wall and electrically connected to the electrode assembly. A portion of the first wall arches outward toward the housing to form a protrusion, and the protrusion has a through-hole. The electrode unit includes a terminal post and a first limiting member and a second limiting member connected via the terminal post. The terminal post passes through the mounting hole. The first limiting member is at least partially disposed on the side of the first wall facing the electrode assembly, and the second limiting member is at least partially disposed on the side of the first wall away from the electrode assembly. Both the first and second limiting members at least partially overlap with the first wall. The side of the protrusion facing the electrode assembly has a receiving groove, and the first limiting member is at least partially received within the receiving groove.

[0005] In the battery cell of this application embodiment, a portion of the first wall of the outer casing is designed to arch outward to form a protrusion. The electrode unit passes through a mounting hole opened in the protrusion, thus providing more mounting space for the electrode assembly within the outer casing. Therefore, without changing the size of the battery cell, the size of the electrode assembly of the battery cell can be increased, which effectively improves the energy density of the battery cell, thereby effectively increasing the driving range of electric vehicles using the battery cells of this application embodiment.

[0006] In some embodiments, at least one of the first limiting member and the second limiting member is provided with a receiving portion, and the pole post cooperates with the receiving portion to achieve assembly connection.

[0007] In this embodiment, the electrode unit is a split structure so that the electrode unit can be installed on and fixed to the first wall.

[0008] In some embodiments, the electrode assembly has a tab portion; the electrode unit is welded to the tab portion via a first fusion portion and is welded to an external device via a second fusion portion; the portion of the first fusion portion on the electrode unit and the portion of the second fusion portion on the electrode unit do not overlap.

[0009] This embodiment adopts a welding connection method, which provides good connection stability between the electrode unit and the tab, as well as between the electrode unit and external devices. It is not easy to loosen, and the welding connection forms a low-impedance, high-strength conductive path through metallurgical or mechanical bonding, resulting in better current conduction capability.

[0010] In some embodiments, the electrode unit has a first end face and a second end face facing away from each other, the first end face facing inwards from the housing and the second end face facing outwards from the housing; a first limiting member is welded to the electrode tab to form a first fusion portion, the orthographic projection of the center of the fusion area formed by the first fusion portion on the first end face onto the target plane does not fall within the orthographic projection of the electrode post onto the target plane, the orthographic projection of the center of the fusion area formed by the second fusion portion on the second end face onto the target plane falls within the orthographic projection of the electrode post onto the target plane, and the target plane is perpendicular to the thickness direction of the first wall.

[0011] This embodiment can reduce or even eliminate the possibility that portions of the first and second welded parts are simultaneously formed on the electrode post, so that even if there is no gap between the first and second welded parts along the thickness direction of the first wall, they can be non-overlapping. This facilitates the reduction of the normal distance between the first and second end faces. In this way, without changing the size of the battery cell, the actual usable space provided for the electrode assembly within the casing can be larger.

[0012] In some embodiments, the second limiting member is integrally formed with the pole post or the second limiting member is provided with a receiving portion and the receiving portion is a blind hole; a first positioning hole is formed in the second end face, each first positioning hole is coaxially arranged with a pole post, and the center of the welding area formed by each second welding portion on the second end face coincides with the center of a first positioning hole.

[0013] This embodiment makes the current conduction path between the second welding part and the pole post shorter. On this basis, by introducing a first positioning hole and setting each first positioning hole coaxially with a pole post, the first positioning hole can provide a positioning function for the welding connection between the electrode unit and the external device, so as to accurately find the welding position and improve the welding accuracy.

[0014] In some embodiments, the first limiting member is provided with a receiving portion and the receiving portion is a through hole, and there are two through holes; the first limiting member is welded to the electrode ear portion to form a first fusion portion, and the fusion area formed by the first fusion portion on the first end face is located between the two through holes.

[0015] In this embodiment, the electrode post is fitted with the through hole on the first limiting member, and the end of the electrode post connected to the first limiting member is exposed on the outside of the electrode unit. When the first limiting member is welded to the electrode ear, the welding position of the first fusion part can be easily found by observing the two electrode posts that fit with the two through holes one by one, without the need to introduce additional positioning holes.

[0016] In some embodiments, in the thickness direction perpendicular to the first wall, the welding area formed by the first welding portion on the first end face is offset from the welding area formed by the second welding portion on the second end face.

[0017] This design allows for a smaller normal distance between the first and second end faces when the tabs are welded to the first limiting member. This increases the usable space within the casing for the electrode assembly without altering the dimensions of the individual battery cells.

[0018] In some embodiments, the welding area formed by the first welding portion on the first end face and the welding area formed by the second welding portion on the second end face at least partially coincide on the orthographic projection of the target plane, and the target plane is perpendicular to the thickness direction of the first wall; the normal distance between the first end face and the second end face is h; the welding depth H1 of the first welding portion in the electrode unit is within a first preset range, the welding depth H2 of the second welding portion in the electrode unit is within a second preset range, and the maximum value H1 of the first preset range is... MAX The maximum value H2 of the second preset range interval MAX The sum of them equals h.

[0019] With this design, when the electrode tab is welded to the first limiting member, h can be reduced to at least H1. MAX With H2 MAX The sum of these factors allows h to be smaller. This allows for a larger actual usable space within the casing for the electrode assembly without changing the size of the individual battery cells.

[0020] In some embodiments, H1 MAX 2mm, H2 MAX The thickness is 3mm. In this embodiment, h can be reduced to a minimum of 5mm, that is, the thickness of the electrode unit can be reduced to a minimum of 5mm.

[0021] In some embodiments, the electrode post includes a first segment and a second segment connected sequentially along the thickness direction of the first wall. The first segment is connected to a second limiting member, and the second segment is located on the side of the protrusion facing the electrode assembly. The second segment cooperates with the receiving portion.

[0022] In some embodiments, the protrusion is provided with a plurality of mounting holes, and the electrode unit is provided with a plurality of pole posts corresponding one-to-one with the plurality of mounting holes.

[0023] This embodiment provides an electrode unit with multiple terminals. By increasing the number of terminals without changing the terminal size, the overcurrent performance of the electrode unit can be improved, which in turn helps to improve the charge and discharge performance of the battery cell.

[0024] In some embodiments, the housing includes a housing and an end cap assembly. The housing has an opening, and the end cap assembly is used to close the opening. The end cap assembly includes an end cap and an insulating member. The end cap serves as a first wall. The insulating member is disposed on the side of the end cap facing inward toward the housing. A portion of the insulating member is arched outward toward the housing to form an arched portion. The arched portion is at least partially received in a receiving groove. An opening is provided through the arched portion. An electrode post is also disposed through the opening. A portion of the arched portion is sandwiched between a first limiting member and a protrusion.

[0025] In this embodiment, the end cap is used as the first wall, and the electrode unit is disposed on the protrusion of the end cap, thereby increasing the height of the actual usable space provided for the electrode assembly inside the housing, and thus increasing the height of the electrode assembly. This embodiment also introduces an insulating component as part of the end cap assembly. The insulating component can be used to insulate and isolate the first limiting member from the end cap, thereby reducing the possibility of electrical conduction between the first limiting member and the end cap, and thus improving the reliability of the battery cell.

[0026] In some embodiments, the orthographic projection of the mounting hole along its through-path onto the arch completely covers the opening.

[0027] This embodiment ensures that no electrical conduction path is formed between the side of the protrusion facing the inside of the housing and the first limiting member, which is beneficial to improving the insulation protection of the end cap by the insulating member.

[0028] In some embodiments, the body on the end cap located around the protrusion and the insulating plate on the insulating member located around the arch are attached, and the first end face of the electrode unit facing into the housing is flush with the side of the insulating plate facing away from the body.

[0029] In this embodiment, by making the first end face flush with the side of the insulating plate facing away from the main body, the first limiting member and the electrode assembly can be reliably connected, while the actual usable height of the space provided for the electrode assembly inside the housing can be as large as possible.

[0030] In some embodiments, the protrusion arches outward from the body located around the protrusion on the first wall, and the protrusion transitions smoothly with the body.

[0031] This embodiment achieves a smooth transition between the protrusion and the body. Since the curvature change of the smooth transition is more uniform, the stress concentration caused by the sharp transition can be reduced.

[0032] An embodiment of the second aspect of this application provides a battery device that includes the battery cell described in the above embodiments.

[0033] An embodiment of the third aspect of this application provides an electrical device that includes a battery cell as described in the above embodiments, the battery cell being used to provide electrical energy, or it includes a battery device as described in the above embodiments, the battery device being used to provide electrical energy.

[0034] An embodiment of the fourth aspect of this application provides an energy storage device, which includes a battery cell as described in the above embodiments, the battery cell being used to store or provide electrical energy, or it includes a battery device as described in the above embodiments, the battery device being used to store or provide electrical energy.

[0035] 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

[0036] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0037] Figure 1 This is a schematic diagram of the vehicle structure according to some embodiments of this application;

[0038] Figure 2 This is an exploded view of the battery device according to some embodiments of this application;

[0039] Figure 3 This is an exploded structural diagram of a battery cell according to some embodiments of this application;

[0040] Figure 4 for Figure 3 The diagram shows an exploded view of the end cap assembly of a single battery cell.

[0041] Figure 5 for Figure 3 A top view of the end cap assembly of the battery cell shown;

[0042] Figure 6 for Figure 5 A partial cross-sectional view of the end cap assembly of the battery cell shown along the AA direction.

[0043] Figure 7 for Figure 3The diagram shows a structural schematic of a scenario in which the end cap assembly and electrode assembly of a battery cell are welded together.

[0044] Figure 8 for Figure 3 A schematic diagram of another scenario in which the end cap assembly and electrode assembly of a battery cell are welded together.

[0045] Figure 9 for Figure 3 The image shows a bottom view of the end cap assembly of the battery cell.

[0046] Explanation of reference numerals in the attached figures:

[0047] 1000 vehicles;

[0048] Battery unit 100, controller 200, motor 300;

[0049] Battery cell assembly 10, battery cell 11, housing 110, first wall 111, electrode assembly 120, tab 121, positive tab 121a, negative tab 121b, main body 122, end cap assembly 130, end cap 131, body 1311, protrusion 1312, mounting hole 13121, electrode unit 132, first limiting member 1321, pole post 1322, second limiting member 1323, first positioning hole 1324, first surface 1325, second surface 1326, third surface 1327, first weld 133, second weld 134, pressure relief mechanism 135, insulating member 136, insulating plate 1361, arched part 1362, fourth surface 1363, sealing member 137, insulating member 138, housing 140;

[0050] Box 20, first box 21, second box 22;

[0051] External device 30. Detailed Implementation

[0052] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein 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 description of the drawings are intended to cover non-exclusive inclusion.

[0054] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0055] In this document, the term "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 throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0056] In the description of the embodiments 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, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0057] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple groups" refers to two or more (including two groups), and "multiple pieces" refers to two or more (including two pieces).

[0058] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0059] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation", "connection", "linking", and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components.

[0060] In this application, the term "parallel" includes not only absolute parallelism but also approximate parallelism as commonly understood in engineering; similarly, "perpendicular" also includes not only absolute perpendicularity but also approximate perpendicularity as commonly understood in engineering. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0061] Currently, judging from market trends, the application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of power battery applications, market demand is also constantly increasing.

[0062] A battery cell, as the smallest unit constituting a power battery, includes an end cap, a housing, electrode assemblies, and other functional components. The end cap closes to the opening of the housing to isolate the internal environment of the battery cell from the external environment. The end cap houses functional components such as electrode units, which connect the electrode assemblies to external devices located outside the housing for the input or output of electrical energy from the battery cell. Taking an opening at the top of the housing as an example, to allow the electrode units to connect to the electrode assemblies and external devices, the electrode units are installed through the end cap. The electrode units have a bottom end and a top end along the through-type direction. The bottom end of the electrode unit is located on the side of the end cap facing inwards from the housing and connects to the electrode assemblies, while the top end of the electrode unit is located on the side of the end cap facing outwards from the housing and connects to external devices.

[0063] Understandably, as a key component on the end cap, the top surface of the electrode assembly usually does not extend beyond the bottom end face of the electrode unit in order to prevent interference between the electrode unit and the electrode assembly. In other words, the normal distance between the bottom end face of the electrode unit and the bottom plate of the housing determines the height of the actual usable space provided for the electrode assembly inside the housing, and thus determines the height of the electrode assembly.

[0064] Currently, some existing battery cells typically have flat end caps. Let H1' be the normal distance between the bottom surface of the end cap and the bottom plate of the casing. The normal distance H2' between the bottom end face of the electrode unit and the bottom plate of the casing is H1' - ΔH, where ΔH is the height of the bottom end face of the electrode unit protruding relative to the bottom surface of the end cap. The remaining height for installing the electrode assembly within this type of casing is H2', and the maximum height of the electrode assembly is H2'. Other existing battery cells have recessed end caps. Specifically, part of the end cap is recessed into the casing to form a concave portion, where the electrode unit is located. In this type of battery cell, the normal distance between the bottom end face of the electrode unit and the bottom plate of the casing is further reduced to H2”, where H2” = H1' - ΔH - ▽H, where ▽H is the height of the recess, i.e., the height of the recess protruding into the casing. The remaining height for installing the electrode assembly within this type of casing is H2”, and the maximum height of the electrode assembly is H2.

[0065] Therefore, when the electrode unit is located on the end cap of the flat structure or in the recess of the sunken end cap, the electrode unit protrudes too much into the housing compared to the end cap. This will greatly compress the actual usable space provided for the electrode assembly in the housing, resulting in a smaller height of the electrode assembly. This affects the energy density of the battery cell and thus the driving range of the electric vehicle.

[0066] Based on the above considerations, a battery cell, battery assembly, electrical device, and energy storage device were designed. A portion of the first wall of the outer casing protrudes outwards to form a raised section, through which the electrode unit passes. In this battery cell, the electrode unit is mounted further away from the electrode assembly, thus increasing the usable space within the casing for the electrode assembly. This provides more room for mounting the electrode assembly within the casing. Therefore, without changing the size of the battery cell, the increased usable space within the casing allows for a larger electrode assembly, thereby effectively increasing the energy density of the battery cell and consequently improving the driving range of electric vehicles using this battery cell.

[0067] The battery devices described in this application can be used, but are not limited to, in electrical equipment such as vehicles, ships, or aircraft, as well as in energy storage devices. A power system for such electrical equipment can be constructed using battery cells and battery devices as described in this application. Similarly, a power system for such energy storage devices can be constructed using battery cells and battery devices as described in this application.

[0068] The energy storage device utilizing a battery as a power system in this application embodiment can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems, etc. The energy storage device can store electrical energy as needed and output it at appropriate times. For example, the energy storage device can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours. The energy storage device provided in this application embodiment can be used in any power system that requires energy storage.

[0069] In some embodiments, the energy storage device is an energy storage container or an energy storage cabinet.

[0070] In some embodiments, the energy storage device may include a cabinet and one or more battery clusters housed within the cabinet. Each battery cluster may include multiple battery units connected in series via a busbar to increase the voltage of the energy storage device. When the energy storage device includes multiple battery clusters, these clusters are connected in parallel to increase the capacity of the energy storage device.

[0071] In this application embodiment, the electrical devices using battery devices as power sources can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0072] It should be understood that the technical solutions described in the embodiments of this application are not limited to the battery devices and electrical equipment described above, but can also be applied to all battery devices including housings and electrical equipment using battery devices. However, for the sake of brevity, the following embodiments are all illustrated using electric vehicles as examples.

[0073] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is provided inside the vehicle 1000, and the battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0074] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0075] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the structure of a battery device 100 according to some embodiments of this application. For example... Figure 2 As shown, the battery device 100 mentioned in the embodiments of this application may include one or more battery cell assemblies 10 for providing voltage and capacity. The battery cell assembly 10 may include multiple battery cells 11, which are connected in series, parallel, or mixed connection via a busbar.

[0076] In some embodiments, the battery cell assembly 10 is typically formed by arranging a plurality of battery cells 11.

[0077] As an example, the battery cell assembly 10 can be a battery module, which is formed by arranging and fixing multiple battery cells 11 together to form an independent module. As an example, the battery module can be formed by bundling multiple battery cells 11 together with cable ties.

[0078] In some embodiments, such as Figure 2 As shown, the battery device 100 can be a battery pack, which includes a housing 20 and one or more individual battery cells 10, with the individual battery cells 10 housed within the housing 20. The housing 20 can be a simple three-dimensional structure such as a single cuboid, cylinder, or sphere, or a complex three-dimensional structure composed of combinations of simple cuboids, cylinders, or spheres. The material of the housing 20 can be an alloy such as aluminum alloy or iron alloy, a polymer such as polycarbonate or polyisocyanurate foam, or a composite material such as glass fiber and epoxy resin.

[0079] As an example, the battery cell assembly 10 can be a battery module, and the battery cell assembly 10 can be housed in the housing 20 by fixing the battery module in the housing 20.

[0080] As an example, the battery cell assembly 10 can also be housed in the housing 20 by directly fixing multiple battery cells 11 to the housing 20.

[0081] As an example, the housing 20 may include a first housing 21 and a second housing 22. The first housing 21 and the second housing 22 are fastened together to form a closed space inside the housing 20 to house the battery cell assembly 10. Here, "closed" refers to covering or closing, and can be either non-sealed or sealed to prevent liquids or other foreign objects from affecting the charging or discharging of the battery cell 11. The first housing 21 may be a top cover or a bottom plate.

[0082] As an example, the housing 20 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that the interior of the housing 20 forms an enclosed space to house the battery cell assembly 10.

[0083] In some embodiments, the housing 20 may be part of the vehicle's chassis structure. For example, a portion of the housing 20 may be at least a portion of the vehicle's floor, or a portion of the housing 20 may be at least a portion of the vehicle's crossbeams and longitudinal beams.

[0084] The battery cell 11 provided in the embodiments of this application can be a secondary battery. A secondary battery refers to a battery cell 11 that can be used again after being discharged by recharging to activate the active material.

[0085] The battery cell 11 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and this application embodiment is not limited to this. As an example, the battery cell 11 can be a cylindrical battery cell, a prismatic battery cell, or a battery cell 11 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, etc., and this application embodiment does not impose any special limitations on this.

[0086] Figure 3 This is an exploded structural diagram of a battery cell 11 according to some embodiments of this application. For example... Figure 3 As shown, the battery cell 11 provided in the embodiments of this application includes a casing 110, an electrode assembly 120, and an electrolyte. The electrode assembly 120 is a component in the battery cell 11 where an electrochemical reaction occurs. The electrode assembly 120 and the electrolyte are housed within the casing 110. As an example, the electrolyte may be liquid, gel-like, or solid.

[0087] Electrode assembly 120 is the component in the battery cell 11 where the electrochemical reaction occurs. The casing 110 may contain one or more electrode assemblies 120. Electrode assembly 120 includes a positive electrode, a negative electrode, and a separator. The battery cell 11 primarily operates by the movement of metal ions between the positive and negative electrode. The positive electrode includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector, and the uncoated positive current collector protrudes beyond the coated positive current collector, serving as the positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive current collector can be aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector, and the negative electrode current collector without the negative electrode active material layer protrudes from the negative electrode current collector with the negative electrode active material layer. The negative electrode current collector without the negative electrode active material layer serves as the negative electrode tab. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon, etc. The material of the separator can be polypropylene or polyethylene, etc.

[0088] The electrode assembly 120 mentioned in this application embodiment has a wound or stacked structure. The electrode assembly 120 can be a wound structure, a stacked structure, or a hybrid structure of both. During processing, the positive electrode sheet, negative electrode sheet, and separator are wound or stacked sequentially to obtain the electrode assembly 120. The positive current collector, negative current collector, and separator constitute the main body 122 of the electrode assembly 120. The electrode assembly 120 also has multiple tabs 121 extending from the main body 122. The multiple tabs 121 include a positive tab 121a and a negative tab 121b. The positive tab 121a is formed by stacking multiple positive tabs together, and the negative tab 121b is formed by stacking multiple negative tabs together. The positive tab 121a and the negative tab 121b can protrude from one end of the main body 122 or from different ends of the main body 122.

[0089] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0090] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0091] In some embodiments, the electrode assembly 120 may be cylindrical, flat, or polygonal in shape.

[0092] As an example, the outer casing 110 can be a steel casing, an aluminum casing, a plastic casing (such as a polypropylene casing), a composite metal casing (such as a copper-aluminum composite casing), or an aluminum-plastic film, etc. In some embodiments, the outer casing 110 can be a sealed structure or a non-sealed structure. As an example, when the outer casing 110 is a non-sealed structure, the outer casing 110 serves to protect the electrode assembly 120, and a sealing bag is also included between the outer casing 110 and the electrode assembly 120. The sealing bag is used to encapsulate the electrode assembly 120 and the electrolyte. Specifically, the sealing bag can be a bag-shaped insulating component or an aluminum-plastic film. When the outer casing 110 is a sealed structure, it is used to encapsulate the electrode assembly 120 and the electrolyte, etc.

[0093] Figure 4 for Figure 3 The diagram shows an exploded view of the end cap assembly 130 of the battery cell 11. Figure 5 for Figure 3 The top view of the end cap assembly 130 of the battery cell 11 shown. Figure 6 for Figure 5 The diagram shows a partial cross-sectional view of the end cap assembly 130 of the battery cell 11 along the AA direction.

[0094] Please refer to some embodiments of this application. Figures 3 to 6 The outer casing 110 has a first wall 111, a portion of which arches outward toward the outer casing 110 to form a protrusion 1312, and the protrusion 1312 is provided with a mounting hole 13121. The battery cell 11 also includes an electrode unit 132, which is disposed on the first wall 111 and electrically connected to the electrode assembly 120. The electrode unit 132 includes a terminal post 1322 and a first limiting member 1321 and a second limiting member 1323 connected to each other through the terminal post 1322. The first limiting member 1321 and the second limiting member 1323 both overlap with at least a portion of the first wall 111. The first limiting member 1321 is at least partially disposed on the side of the first wall 111 facing the electrode assembly 120, and the second limiting member 1323 is at least partially disposed on the side of the first wall 111 away from the electrode assembly 120. The protrusion 1312 has a receiving groove on the side facing the electrode assembly 120, and the first limiting member 1321 is at least partially received in the receiving groove.

[0095] In other words, the first wall 111 includes a body 1311 and a protrusion 1312. The protrusion 1312 arches outward from the body 1311 toward the outer casing 110. The body 1311 can be regarded as the non-arched part of the first wall 111, and the body 1311 is located around the protrusion 1312. When processing the battery cell 11, any one of the following processes can be used: stamping, rolling, molding, or electromagnetic forming, so that part of the first wall 111 arches to form the protrusion 1312.

[0096] The shape of the protrusion 1312 is not limited and can be designed according to the shape and number of mounting holes 13121. The shape of the mounting holes 13121 includes, but is not limited to, rectangular, oblong, etc. Figure 4 The shape of the electrode post 1322 of the electrode unit 132 is adapted to the shape of the mounting hole 13121, so that the electrode post 1322 can be inserted into the mounting hole 13121. The materials of the first limiting member 1321, the electrode post 1322 and the second limiting member 1323 can all be selected from any one or more conductive metals such as copper, aluminum, silver and nickel. The first limiting member 1321 and the second limiting member 1323 are located on different sides of the first wall 111 along its own thickness direction, with the first limiting member 1321 located inside the outer shell 110 and the second limiting member 1323 located outside the outer shell 110.

[0097] Since both the first limiting member 1321 and the second limiting member 1323 overlap at least partially with the first wall 111, after the electrode unit 132, which is a split structure, is installed on the first wall 111, the first limiting member 1321 and the second limiting member 1323 cannot pass through the mounting hole 13121. Therefore, the fit between the first limiting member 1321 and the circumferential edge of the mounting hole 13121 on the protrusion 1312, and the fit between the second limiting member 1323 and the circumferential edge of the mounting hole 13121, can restrict the displacement of the electrode unit 132 along the thickness direction of the first wall 111, thereby fixing the position of the electrode unit 132. In some embodiments, the mounting hole 13121 is circular, and both the first limiting member 1321 and the second limiting member 1323 are cylindrical, and the outer diameters of the first limiting member 1321 and the second limiting member 1323 are both larger than the diameter of the mounting hole 13121.

[0098] The electrode assembly 120 is electrically connected to the external device 30 via the electrode unit 132 to output current to the external device 30. When using the battery cell 11, battery device, etc., which are provided with the embodiments of this application to form an electrical device or energy storage device, the external device 30 may specifically refer to a busbar component.

[0099] The battery cell 11 provided in this application embodiment features a protrusion 1312 formed by a portion of the first wall 111 of the outer casing 110 arching outwards from the casing 110. An electrode unit 132 is mounted on the protrusion 1312, and at least a portion of the first limiting member 1321 is accommodated in a receiving groove on the side of the protrusion 1312 facing the electrode assembly 120, such that the portion of the first limiting member 1321 accommodated in the receiving groove does not protrude compared to the portion of the first wall 111 that is not arched. This expands the actual usable space provided within the casing 110 for the electrode assembly 120, meaning that more space is reserved within the casing 110 for the installation of the electrode assembly 120. Thus, without changing the size of the battery cell 11, the size of the electrode assembly 120 of the battery cell 11 can be increased, thereby increasing the active material capacity of the battery cell 11 and consequently increasing the energy density of the battery cell 11. The driving range of electric vehicles using the battery cell 11 of this application embodiment can be correspondingly improved.

[0100] According to some embodiments of this application, at least one of the first limiting member 1321 and the second limiting member 1323 may be provided with a receiving portion, and the pole post 1322 cooperates with the receiving portion to be assembled and connected.

[0101] The receiving portion can be either a through hole or a blind hole. The centerline of the receiving portion is collinear with the centerline of the mounting hole 13121. The shape of the receiving portion is adapted to the shape of the terminal post 1322 and the shape of the mounting hole 13121. As disclosed herein, the terminal post 1322 and the receiving portion can be fitted together using any of the following techniques: screwing, riveting, or interference fit, so that the terminal post 1322 is assembled and connected to the first limiting member 1321 and / or the second limiting member 1323 with the receiving portion. Alternatively, welding or bonding techniques can be used to assemble and connect the terminal post 1322 to the first limiting member 1321 and / or the second limiting member 1323 with the receiving portion.

[0102] In this embodiment, the electrode unit 132 is a split structure so that the electrode unit 132 can be installed on the first wall 111 and fixed.

[0103] Figure 7 for Figure 3 This is a schematic diagram of a configuration in which the end cap assembly 130 and the electrode assembly 120 are welded together in a single battery cell 11. Figure 8 for Figure 3 This is a schematic diagram illustrating another configuration where the end cap assembly 130 and the electrode assembly 120 are welded together in the battery cell 11. Please refer to some embodiments of this application. Figure 7 and Figure 8The electrode unit 132 can be welded to the tab portion 121 via the first fusion portion 133, and can be welded to the external device 30 via the second fusion portion 134. Furthermore, the portions of the first fusion portion 133 and the second fusion portion 134 on the electrode unit 132 can be configured to not overlap; that is, the portions of the first fusion portion 133 and the second fusion portion 134 on the electrode unit 132 have no overlapping portion.

[0104] The welding can be performed by any one of laser welding, resistance welding, ultrasonic welding, pressure welding, or brazing to form the first welded part 133 and the second welded part 134.

[0105] In this embodiment, when processing the battery cell 11, the electrode unit 132 and the tab portion 121 can be welded together to form a first weld portion 133. Then, during the process of welding the electrode unit 132 and the external device 30 to form a second weld portion 134, the molten pool formed does not overlap with the first weld portion 133.

[0106] By adopting a welding connection method, on the one hand, the connection between electrode unit 132 and electrode tab 121, as well as between electrode unit 132 and external device 30, has good connection stability and is not easy to loosen. On the other hand, the welding connection forms a low-resistance, high-strength conductive path through metallurgical or mechanical bonding, resulting in better current conduction capability.

[0107] In some related technologies, an adapter plate is typically used as an intermediate medium to achieve electrical connection between the electrode unit 132 and the tab 121, with the adapter plate sandwiched between the electrode unit 132 and the tab 121. In this method, due to the presence of the adapter plate, the adapter plate occupies space within the housing 110 along the thickness direction of the first wall 111, thus compressing the actual usable space within the housing 110 for the electrode assembly 120 along the thickness direction of the first wall 111. However, in this embodiment, the electrode unit 132 and the tab 121 are directly connected by welding, eliminating the need for an additional adapter plate. This eliminates the negative impact on the energy density of the battery cell 11 caused by the adapter plate occupying space within the housing 110.

[0108] Furthermore, by ensuring that the portion of the first welded portion 133 on the electrode unit 132 and the portion of the second welded portion 134 on the electrode unit 132 do not overlap, the first welded portion 133 and the second welded portion 134 are independent of each other. This can weaken or even eliminate the possibility that the heat generated during the welding process between the electrode unit 132 and the external device 30 may cause the formed first welded portion 133 to remelt. In this way, the possibility of the first welded portion 133 causing changes in the metal grain structure, generating defects such as pores or cracks due to remelting can be reduced. This is beneficial to ensure that the formed first welded portion 133 still has good strength and better quality after the electrode unit 132 and the external device 30 are welded.

[0109] In some embodiments, both the first limiting member 1321 and the second limiting member 1323 are provided with receiving portions, and the receiving portions are through holes, so that the axial end faces of both ends of the pole post 1322 are exposed on the outside of the electrode unit 132. Based on this, the first end of the pole post 1322 can be welded to the tab portion 121 to form a first weld portion 133, while the second end can be welded to the external device 30 to form a second weld portion 134. In this example, it is more likely that the ends of the first weld portion 133 and the second weld portion 134 are located on a straight line parallel to the thickness direction of the first wall 111. To ensure that the first weld portion 133 and the second weld portion 134 do not overlap, the first weld portion 133 and the second weld portion 134 must be spaced apart along the thickness direction of the first wall 111, that is, there is a gap between the ends of the first weld portion 133 and the second weld portion 134 along the thickness direction of the first wall 111.

[0110] According to some embodiments of this application, the electrode unit 132 has a first end face and a second end face facing away from each other. The first end face faces the electrode assembly 120, and the second end face faces outward from the housing 110. The first limiting member 1321 is welded to the electrode tab 121 to form a first welded portion 133. The orthographic projection of the center of the welded area formed by the first welded portion 133 on the first end face onto the target plane may not fall within the orthographic projection of the electrode post onto the target plane. The orthographic projection of the center of the welded area formed by the second welded portion 134 on the second end face onto the target plane may fall within the orthographic projection of the electrode post 1322 onto the target plane. The target plane is perpendicular to the thickness direction of the first wall 111.

[0111] This embodiment can reduce or even eliminate the possibility that a portion of the first welded portion 133 and a portion of the second welded portion 134 are simultaneously formed on the electrode post 1322. Thus, even if the first welded portion 133 and the second welded portion 134 have no spacing along the thickness direction of the first wall 111, the first welded portion 133 and the second welded portion 134 can be made to not overlap, thereby facilitating a reduction in the normal distance h between the first end face and the second end face. In this way, without changing the size of the battery cell 11, the electrode unit 132 is reliably welded to the tab portion 121 and the external device 30, while providing a larger actual usable space within the housing 110 for the electrode assembly 120.

[0112] Specifically, in the technical solution where the first end of the pole post 1322 is welded to the tab 121 to form a first welded portion 133, and the second end is welded to the external device 30 to form a second welded portion 134, as mentioned above, in order to ensure that the portions of the first welded portion 133 and the second welded portion 134 on the pole post 1322 do not overlap, the first welded portion 133 and the second welded portion 134 must have a gap along the thickness direction of the first wall 111. In this case, h should satisfy: h≥H1 MAX +H2 MAX +△h, where △h is the distance between the first welded portion 133 and the second welded portion 134, and △h is a positive number. In the technical solution where the first limiting member 1321 is welded to the electrode lug 121 to form the first welded portion 133, and the orthographic projection of the center of the welded area formed by the first welded portion 133 on the first end face onto the target plane does not fall within the orthographic projection of the pole post 1322 onto the target plane, the absence of distance between the first welded portion 133 and the second welded portion 134 along the thickness direction of the first wall 111 also allows the first welded portion 133 and the second welded portion 134 to satisfy the condition of non-overlapping. Therefore, the minimum limit value of h can be less than H1. MAX +H2 MAX +△h.

[0113] According to some embodiments of this application, the second limiting member 1323 and the electrode post 1322 can be integrally formed, and the first limiting member 1321 is provided with a receiving portion; alternatively, the second limiting member 1323 can be provided with a receiving portion, and the receiving portion is a blind hole. The second end face can be further recessed to form a first positioning hole 1324, each first positioning hole 1324 being coaxially arranged with one electrode post 1322, and the center of the welding area formed by each second welding portion 134 on the second end face coinciding with the center of one first positioning hole 1324. The number of first positioning holes 1324, the number of electrode posts 1322 in the electrode unit 132, the number of mounting holes 13121 in the protrusion 1312, and the number of second welding portions 134 are the same.

[0114] It is understood that the first positioning hole 1324 is formed on the second limiting member 1323. The welding area formed on the second end face of the second welding portion 134 is... Figure 5 The area shown is S1, and the shape of the fusion area S1 includes, but is not limited to, circles, rectangles, etc.

[0115] As an example, in a technical solution where the second limiting member 1323 has a receiving portion and the receiving portion is a blind hole, the end of the pole post 1322 connected to the second limiting member 1323 does not protrude outside the electrode unit 132. Similarly, in a technical solution where the second limiting member 1323 and the pole post 1322 are integrally formed, the end of the pole post 1322 connected to the second limiting member 1323 also does not protrude outside the electrode unit 132.

[0116] exist Figures 3 to 6 In the specific embodiment shown, the protrusion 1312 has two mounting holes 13121, the electrode unit 132 has two pole posts 1322, and there are also two first positioning holes 1324. The two first positioning holes 1324 are coaxially arranged corresponding to the two pole posts 1322. Please refer to... Figure 7 and Figure 8 Two second welding portions 134 are provided, and the centers of the welding areas formed by the two second welding portions 134 on the second end face coincide with the centers of the two first positioning holes 1324. Of course, in other embodiments of this application, the number of pole posts 1322 of the electrode unit 132 can also be one, three, four or more.

[0117] In this embodiment, the center of the electrode unit 132 is collinear with the center of the pole post 1322 when welding the external device 30. This results in a shorter current conduction path between the formed second welded portion 134 and the pole post 1322, allowing the current to be quickly conducted from the pole post 1322 to the second welded portion 134 and then to the external device 30, thus improving current conduction capability. Furthermore, the end of the pole post 1322 connected to the second limiting member 1323 does not protrude from the outside of the electrode unit 132. This embodiment also introduces a first positioning hole 1324, with each first positioning hole 1324 coaxially arranged with one pole post 1322. The first positioning hole 1324 provides positioning for the welding connection between the electrode unit 132 and the external device 30, facilitating accurate welding and improving welding precision.

[0118] In the technical solution where the second limiting member 1323 and the electrode post 1322 are integrally formed and the first limiting member 1321 is provided with a receiving portion, the electrode unit 132 can be installed on the first wall 111. Thanks to the integral forming of the second limiting member 1323 and the electrode post 1322, the assembly process between the second limiting member 1323 and the electrode post 1322 can be saved, the assembly efficiency can be improved, and the structural strength of the electrode unit 132 can be improved without increasing the cost.

[0119] According to some embodiments of this application, the first limiting member 1321 and the electrode post 1322 can be integrally formed, and the second limiting member 1323 is provided with a receiving portion; alternatively, the first limiting member 1321 can be provided with a receiving portion, and the receiving portion is a blind hole. In this example, the end of the electrode post 1322 connected to the first limiting member 1321 does not protrude outside the electrode unit 132. To facilitate locating the welding position of the first limiting member 1321 and the electrode tab 121, a second positioning hole can also be recessed on the first end face, and the center of the welding area formed by the first welding portion 133 on the first end face coincides with the center of the second positioning hole. Thus, the second positioning hole provides a positioning function for welding the first limiting member 1321 and the electrode tab 121.

[0120] Figure 9 for Figure 3 The image shows a bottom view of the end cap assembly 130 of the battery cell 11. According to some embodiments of this application, the first limiting member 1321 may have a receiving portion, and the receiving portion may be a through hole, such as… Figure 9 As shown, two through holes can be provided. The first limiting member 1321 is welded to the electrode tab 121 to form a first welded portion 133, and the welded area formed on the first end face of the first welded portion 133 is located between the two through holes.

[0121] The side of the first limiting member 1321 facing away from the second limiting member 1323 is the first surface 1325, the axial end face of the end of the pole post 1322 connected to the first limiting member 1321 is the second surface 1326, and the side of the second limiting member 1323 facing away from the first limiting member 1321 is the third surface 1327. In this example, the second surface 1326 can be located between the first surface 1325 and the third surface 1327, or, as... Figure 6 As shown, the second surface 1326 can also be flush with the first surface 1325 so that the first end of the pole post 1322 does not protrude out of the through hole.

[0122] The first welded portion 133 forms a welded area on the first end face. Figure 9The area shown is S2, and the shape of the welding area S2 includes, but is not limited to, circles and rectangles. It is understood that each through-hole mates with one electrode post 1322; therefore, in this embodiment, the electrode unit 132 has two electrode posts 1322, and the number of second welding portions 134 formed by welding the electrode unit 132 to the external device 30 is also two. The welding area S2 formed by the first welding portion 133 on the first end face is also located between the two electrode posts 1322. The two through-holes and the two electrode posts 1322 can be symmetrical on both sides of the welding area formed by the first welding portion 133 on the first end face.

[0123] In this embodiment, the pole post 1322 is engaged with the through hole on the first limiting member 1321. The end of the pole post 1322 connected to the first limiting member 1321 is exposed on the outside of the electrode unit 132. When the first limiting member 1321 is welded to the electrode ear 121, by observing the two pole posts 1322 that are engaged with the two through holes one by one, the welding position of the first fusion part 133 can be easily found between the two pole posts 1322 without the need to introduce additional positioning holes.

[0124] Furthermore, the pole post 1322 and the through hole on the first limiting member 1321 can be riveted or interference-fitted.

[0125] Understandably, in the technical solution where the terminal post 1322 and the first limiting member 1321 are bonded together with adhesive, as the battery cell 11 operates for a period of time, the battery cell 11 will generate heat and rise in temperature. The adhesive is prone to failure under high temperature conditions, affecting the connection reliability between the terminal post 1322 and the first limiting member 1321. That is, in this example, the connection reliability between the terminal post 1322 and the first limiting member 1321 is easily affected by high temperature.

[0126] It is understandable that in the technical solution where the pole post 1322 and the first limiting member 1321 are connected by welding, and the pole post 1322 and the electrode lug 121 are electrically connected by welding, the pole post 1322 and the first limiting member 1321 are welded to form a weld. The weld will have a portion protruding from the first surface 1325 and the second surface 1326. On this basis, in order to prevent the electrode lug 121 from interfering with the weld while the pole post 1322 and the electrode lug 121 are welded, an additional conductive plate is often needed between the pole post 1322 and the electrode lug 121. The space occupied by the conductive plate in the thickness direction of the first wall 111 is used to accommodate the portion of the weld protruding from the pole post 1322, so that the electrode lug 121 and the weld are avoided. It is evident that this technical solution employs welding technology, which can mitigate the impact of high temperature on the connection reliability between the electrode post 1322 and the first limiting member 1321. However, it introduces a conductive plate, which occupies the space within the housing 110 along the thickness direction of the first wall 111. This results in the actual usable space provided within the housing 110 for the electrode assembly 120 being compressed, which in turn leads to the compression of the size of the electrode assembly 120, affecting the energy density of the battery cell 11.

[0127] In this embodiment, the electrode post 1322 is riveted or interference-fitted to the through hole on the first limiting member 1321. The riveting and interference fit methods are mechanical fixing methods, which have high connection strength and can maintain a reliable connection even in high-temperature environments. They do not introduce welds and conductive plates, which can effectively avoid the compression of the actual usable space provided for the electrode assembly 120 in the shell 110 due to the space occupied by welds and conductive plates along the thickness direction of the first wall 111 inside the shell 110. In this way, the negative impact of the introduced welds and conductive plates on the energy density of the battery cell 11 can be eliminated.

[0128] According to some embodiments of this application, such as Figure 5 , Figure 8 and Figure 9 As shown, in the thickness direction perpendicular to the first wall 111, the welding area S2 formed by the first welding portion 133 on the first end face and the welding area S1 formed by the second welding portion 134 on the second end face can be completely offset. In this example, the ends of the first welding portion 133 and the second welding portion 134 can be spaced apart or flush in the thickness direction of the first wall 111, or the end of the second welding portion 134 can be located between the end of the first welding portion 133 and the first end face, and the portion of the first welding portion 133 on the electrode unit 132 and the portion of the second welding portion 134 on the electrode unit 132 have no intersection or overlap.

[0129] The fact that the welding area S1 and the welding area S2 are completely offset can be understood as the fact that the orthographic projections of the welding area S1 and the welding area S2 on the target plane do not coincide, and the target plane is perpendicular to the thickness direction of the first wall 111.

[0130] The end of the second weld portion 134 can be located between the end of the first weld portion 133 and the first end face. The first weld portion 133 has a weld depth H1 within a first preset range at the electrode unit 132, where the maximum value of the first preset range is H1. MAX The second welded portion 134 has a weld depth H2 within the electrode unit 132 that is within a second preset range, and the maximum value of the second preset range is H2. MAX The normal distance between the first end face and the second end face is h. At this time, the minimum limit value of h can be narrowed to less than H1. MAX +H2 MAX It is understood that when at least one of the first weld portion 133 and the second weld portion 134 does not employ the maximum permissible weld depth, there is a gap between the first weld portion 133 and the second weld portion 134 in the thickness direction of the first wall 111, or, along the through direction of the mounting hole 13121, the distance between the end of the first weld portion 133 and the end of the second weld portion 134 is equal to 0 millimeters (mm).

[0131] In this paper, the normal distance h is defined as the minimum perpendicular distance between the first end face and the second end face. The minimum values ​​of both the first and second preset ranges are positive numbers, and both the first and second preset ranges can be designed based on experience and actual working conditions.

[0132] In this embodiment, based on the welding connection between the tab 121 and the first limiting member 1321, when the welding area S2 formed by the first welding part 133 on the first end face and the welding area S1 formed by the second welding part 134 on the second end face are completely misaligned, h can be at least reduced to less than H1. MAX With H2 MAX The sum of these two conditions is sufficient to ensure that the first welded portion 133 and the second welded portion 134 do not overlap.

[0133] According to some embodiments of this application, such as Figure 5 , Figure 7 and Figure 9 As shown, the welding area S2 formed by the first welding portion 133 on the first end face and the welding area S1 formed by the second welding portion 134 on the second end face can at least partially coincide in the orthographic projection of the target plane, and the target plane is perpendicular to the penetration direction of the mounting hole 13121. The normal distance between the first end face and the second end face is h. The welding depth H1 of the first welding portion 133 in the electrode unit 132 is within a first preset range, and the welding depth H2 of the second welding portion 134 in the electrode unit 132 is within a second preset range. The maximum value H1 of the first preset range is... MAX The maximum value H2 of the second preset range interval MAX The sum equals h, which is H1 MAX +H2 MAX =h.

[0134] In other words, in this example, when both the first weld portion 133 and the second weld portion 134 adopt the maximum allowable weld depth, the distance between the ends of the first weld portion 133 and the second weld portion 134 along the thickness direction of the first wall 111 is equal to 0 mm. When at least one of the first weld portion 133 and the second weld portion 134 does not adopt the maximum allowable weld depth, the first weld portion 133 and the second weld portion 134 are spaced apart along the thickness direction of the first wall 111.

[0135] In this embodiment, based on the welding connection between the tab 121 and the first limiting member 1321, when the welding area S2 and the welding area S1 can at least partially overlap in their orthographic projections onto the target plane, h can be at least limited to equal H1. MAX With H2 MAX The sum of these two conditions is sufficient to ensure that the first welded portion 133 and the second welded portion 134 do not overlap.

[0136] In summary, compared to the technical solution where the tab 121 and the electrode post 1322 are welded together via the first fusion portion 133, the h in this embodiment can be smaller, provided that the first fusion portion 133 and the second fusion portion 134 do not overlap. It should be noted that, compared to the technical solution where the fusion region S2 and the fusion region S1 are completely offset, the technical solution where the fusion region S2 and the fusion region S1 can at least partially overlap in the orthographic projection of the target plane not only ensures that the first fusion portion 133 and the second fusion portion 134 do not overlap, but also allows for a more compact arrangement of the first fusion portion 133 and the second fusion portion 134 on the electrode unit 132.

[0137] Specifically, in Figure 7 In the example shown, h can be narrowed down to at least H1. MAX With H2 MAX In summary, during the processing of the battery cell 11, even if the first welded portion 133 and the second welded portion 134 both adopt the maximum allowable welding depth, there will be no overlap between the first welded portion 133 and the second welded portion 134. This reduces the risk of the formed first welded portion 133 being remelted due to the heat generated during the welding process between the electrode unit 132 and the external device 30.

[0138] According to some embodiments of this application, H1 MAX For example, it could be 2mm, H2 MAX For example, it can be 3mm.

[0139] exist Figure 7 In the example shown, h can be reduced to a minimum of 5 mm, and the thickness of electrode unit 132 can be a minimum of 5 mm.

[0140] According to some embodiments of this application, the electrode post 1322 may be specifically designed to include a first segment and a second segment connected sequentially along the thickness direction of the first wall 111. The first segment is connected to the second limiting member 1323, and the second segment is located on the side of the protrusion 1312 facing the electrode assembly 120. The second segment cooperates with the receiving portion.

[0141] Please continue to refer to this. Figure 6 The first segment passes through the mounting hole 13121, and the cross-sectional area of ​​the first segment in the thickness direction perpendicular to the first wall 111 is greater than the cross-sectional area of ​​the second segment in the thickness direction perpendicular to the first wall 111. For example, both the first and second segments are cylindrical, and the outer diameter of the first segment is greater than the outer diameter of the second segment.

[0142] According to some embodiments of this application, the protrusion 1312 may be provided with a plurality of mounting holes 13121, and the electrode unit 132 is provided with a plurality of pole posts 1322 corresponding one-to-one with the plurality of mounting holes 13121.

[0143] Please continue to refer to this. Figure 4 and Figure 6 For example, the number of mounting holes 13121 opened on the protrusion 1312 is two, and the electrode unit 132 is also provided with two pole posts 1322, each pole post 1322 passing through a corresponding mounting hole 13121. Of course, in other embodiments of this application, the number of mounting holes 13121 opened on the protrusion 1312 can also be three, four or more.

[0144] In the technical solution where two mounting holes 13121 are provided on the protrusion 1312, the protrusion 1312 can be waist-shaped, having two arc-shaped segments and a straight segment between them. The two mounting holes 13121 can be arranged concentrically with the two arc-shaped segments. Compared to other shapes such as rectangles, the waist-shaped protrusion 1312 has no sharp corners, which helps reduce stress concentration. By designing the two mounting holes 13121 to be concentrically arranged with the two arc-shaped segments, the two arc-shaped segments and the two mounting holes 13121 can be symmetrically arranged about the straight segment. This helps to improve the uniformity of stress distribution of the electrode unit 132 acting on the protrusion 1312, and also helps to determine the reference of the mounting holes 13121 during the machining of the mounting holes 13121 on the protrusion 1312, thus reducing machining difficulty and improving machining accuracy.

[0145] In this embodiment, the electrode unit 132 has multiple terminals 1322. Without changing the size of the terminals 1322, the overcurrent performance of the electrode unit 132 can be improved by increasing the number of terminals 1322, which in turn helps to improve the charging and discharging performance of the battery cell 11.

[0146] Based on some embodiments of this application, please continue to refer to Figures 3 to 9 The housing 110 may specifically include a housing 140 and an end cap assembly 130. The housing 140 has an opening, and the end cap assembly 130 is used to close the opening. The housing 140 and the end cap 131 together enclose a mounting cavity, which provides mounting space for components such as the electrode assembly 120. The end cap assembly 130 may specifically include an end cap 131 and an insulating member 136. The insulating member 136 is disposed on the side of the end cap 131 facing inward toward the housing 110.

[0147] The housing 140 is an assembly used to cooperate with the end cap assembly 130 to form the internal environment of the battery cell 11, wherein the formed internal environment can accommodate the electrode assembly 120, the electrolyte, and other components. The housing 140 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 140 can be determined according to the specific shape and size of the electrode assembly 120. The material of the housing 140 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this.

[0148] End cap 131 refers to a component that covers the opening of housing 140 to isolate the internal environment of battery cell 11 from the external environment. Not limited to this, the shape of end cap 131 can be adapted to the shape of housing 140 to fit the housing 140. In some embodiments, such as... Figure 3 As shown, the battery cell 11 is a prismatic battery cell, the electrode assembly 120 is flat, and both the housing 140 and the end cap 131 are cuboid in shape. In some embodiments, the battery cell 11 is a cylindrical battery cell, the electrode assembly 120 is cylindrical, and both the housing 140 and the end cap 131 are cylindrical. Optionally, the end cap 131 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 131 is not easily deformed when subjected to compression and impact, enabling the battery cell 11 to have higher structural strength and improve safety performance. The end cap 131 can also be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. As an example, the end cap 131 can also be provided with a pressure relief mechanism 135 for releasing internal pressure when the internal pressure or temperature of the battery cell 11 reaches a threshold.

[0149] It is understood that either the housing 140 or the end cap 131 can be used as the first wall 111.

[0150] In some embodiments, the housing 140 can be used as a first wall 111, that is, the electrode unit 132 is disposed on the protrusion 1312 of the housing 140.

[0151] In some embodiments, such as Figure 3 and Figure 4As shown, end cap 131 can be used as first wall 111. Part of insulating member 136 arches outward toward housing 110 to form arch 1362, arch 1362 is at least partially received in receiving groove, arch 1362 is provided with an opening through which pole post 1322 is also provided, arch 1362 can be configured such that it is partially sandwiched between first limiting member 1321 and protrusion 1312.

[0152] In other words, the insulating component 136 includes an insulating plate 1361 and an arched portion 1362. The arched portion 1362 arches outward from the insulating plate 1361 toward the outer casing 110. The insulating plate 1361 can be considered as the non-arched portion of the insulating component 136, and the insulating plate 1361 is located around the arched portion 1362. During the processing of the battery cell 11, any one of the following processes can be used: stamping, rolling, molding, or electromagnetic forming, so that the arched portion 1362 is formed by the partial arching of the insulating component 136.

[0153] The insulating plate 1361 is attached to the side of the body 1311 facing the electrode assembly 120, and the arched portion 1362 is at least partially attached to the side of the protrusion 1312 facing the electrode assembly 120. The shape of the arched portion 1362 can be adapted to the shape of the protrusion 1312, so that the fit between the arched portion 1362 and the protrusion 1312 is good. The material of the insulating component 136 can be any of inorganic insulating materials (such as ceramics) or organic polymer insulating materials. Among them, the organic polymer insulating materials can be, but are not limited to, polyethylene (PE), polypropylene (PP), polyimide (PI), polyvinyl chloride (PVC), epoxy resin, etc.

[0154] The number of openings in the arched portion 1362 is equal to the number of poles 1322 in the electrode unit 132, such that each pole 1322 corresponds to one opening. The shape of the opening is adapted to the shape of the pole 1322. The arched portion 1362 can be used to insulate and isolate the first limiting member 1321 from the end cap 131.

[0155] In this embodiment, the end cap 131 serves as the first wall 111, and the electrode unit 132 is disposed on the protrusion 1312 of the end cap 131, meaning the mounting position of the electrode unit 132 is raised. This increases the height of the actual usable space provided within the housing 110 for the electrode assembly 120, allowing for a greater height of the electrode assembly 120 without changing the overall height of the battery cell 11. This embodiment also introduces an insulating member 136 as part of the end cap assembly 130. The insulating member 136 can be used to insulate and isolate the first limiting member 1321 from the end cap 131, thereby reducing the possibility of electrical conduction between the first limiting member 1321 of the electrode unit 132 and the end cap 131, thus improving the reliability of the battery cell 11.

[0156] In one specific embodiment, please refer to Figures 3 to 6 As shown, the battery cell 11 is a prismatic battery cell with only one opening located at the top of the housing 140. There is also one end cap assembly 130. Two electrode units 132 are provided and connected to the positive electrode tab 121a and the negative electrode tab 121b, respectively. Compared to the technical solution where the electrode units 132 are mounted on the flat end cap 131, in this example, the height T of the protrusion 1312 is released, increasing the actual usable space provided within the housing 140 for the electrode assembly 120 by T compared to H2'. Consequently, the height of the electrode assembly 120 can be increased by T accordingly.

[0157] Please continue to refer to this. Figure 6 The arched portion 1362 can also be designed to cover the circumferential side surface of the first limiting member 1321. In this way, on the one hand, the arched portion 1362 can prevent the circumferential side surface of the first limiting member 1321 from being electrically connected to the end cap 131, thus improving the insulation reliability between the first limiting member 1321 and the end cap 131. On the other hand, the mating relationship between the arched portion 1362 and the circumferential side surface of the first limiting member 1321 can serve a limiting function, thereby reducing the possibility of the first limiting member 1321 moving relative to the outer shell 110 in the thickness direction perpendicular to the first wall 111.

[0158] According to some embodiments of this application, the orthographic projection of the mounting hole 13121 along its own through direction onto the arch 1362 can completely cover the opening.

[0159] As an example, the orthographic projection of the mounting hole 13121 along its through-path on the arched portion 1362 completely coincides with the opening. For example, both the mounting hole 13121 and the opening are circular, and the diameter of the mounting hole 13121 can be equal to the diameter of the opening. In this case, the wall of the mounting hole 13121 and the wall of the opening are coplanar. As an example, the orthographic projection of the mounting hole 13121 along its through-path on the arched portion 1362 completely covers the opening. For example, both the mounting hole 13121 and the opening are circular, and the diameter of the mounting hole 13121 can be larger than the diameter of the opening. In this case, a portion of the arched portion 1362 protrudes into the mounting hole 13121 relative to the wall of the mounting hole 13121 along a direction perpendicular to the thickness of the first wall 111.

[0160] In this embodiment, by ensuring that the orthogonal projection of the mounting hole 13121 along its through-path onto the arched portion 1362 completely covers the opening, an electrical conduction path is not formed between the protrusion 1312 and the first limiting member 1321. This is beneficial to improving the insulation protection of the end cover 131 by the insulating member 136, resulting in better electrical isolation and thus improving the safety of the battery cell 11.

[0161] According to some embodiments of this application, the body 1311 on the end cap 131 located around the protrusion 1312 and the insulating plate 1361 on the insulating member 136 located around the arch 1362 are attached together. The side of the insulating plate 1361 facing away from the body 1311 is the fourth surface 1363. The first end face of the electrode unit 132 facing into the housing 140 and the fourth surface 1363 can be configured to be flush.

[0162] In other words, the first end face and the fourth surface 1363 are coplanar. It can be understood that in the technical solution where the end cap assembly 130 also has an insulating member 136, the height of the actual usable space provided inside the housing 110 for the electrode assembly 120 depends on the one of the first end face and the fourth surface 1363 that is farther away from the second end face.

[0163] Compared to the technical solution where the fourth surface 1363 is located between the first and second end faces, assuming other parameters such as the thickness of the insulating plate 1361 and the end cap 131 are the same, in this embodiment, the first limiting member 1321 will not protrude from the insulating plate 1361, thus allowing for a greater actual usable space height within the outer casing 110 for the electrode assembly 120. Compared to the technical solution where the first end face is located between the fourth surface 1363 and the second end face, in this embodiment, the insulating plate 1361 will not protrude from the first end face, thus preventing interference with the contact between the first limiting member 1321 and the electrode assembly 120. In summary, by making the first end face flush with the fourth surface 1363, this embodiment ensures reliable contact between the first limiting member 1321 and the electrode assembly 120 while maximizing the actual usable space height within the outer casing 110 for the electrode assembly 120.

[0164] According to some embodiments of this application, the protrusion 1312 arches outward from the body 1311 located around the protrusion 1312 on the first wall 111 toward the outer shell 110, and the protrusion 1312 and the body 1311 can transition smoothly.

[0165] Compared to straight-edge transitions or stepped transitions between the protrusion 1312 and the body 1311, this embodiment achieves a smooth transition between the protrusion 1312 and the body 1311. Since the curvature change of a smooth transition is more uniform, this reduces stress concentration caused by sharp transitions.

[0166] According to some embodiments of this application, the end cap assembly 130 may further include a seal 137, which is configured to seal the gap between the hole wall of the mounting hole 13121 and the circumferential wall of the terminal post 1322, and to seal the gap between the first wall 111 and the second limiting member 1323, so as to reduce the possibility of water or impurities entering the battery cell 11 through the gap, thereby improving the reliability of the battery cell 11.

[0167] According to some embodiments of this application, the end cap assembly 130 may further include an insulating member 138 for insulatingly isolating the second limiting member 1323 and the end cap 131. Specifically, the insulating member 138 includes a first insulating ring and a second insulating ring connected by a bend, the first insulating ring being stacked between the protrusion 1312 and the second limiting member 1323, and the second insulating ring covering the circumferential side of the second limiting member 1323.

[0168] 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.

[0169] The following is a further explanation of a specific aspect of this application, such as... Figures 3 to 7 As shown, the battery cell 11 is a prismatic battery cell. The battery cell 11 includes a housing 110, an end cap assembly 130, and two flat electrode assemblies 120. The housing 110 includes a shell 140 and an end cap assembly 130. The top of the shell 140 has an opening. The end cap assembly 130 includes an end cap 131, an insulating member 136, and two electrode units 132. The shell 140 and the end cap 131 together form a mounting cavity. The end cap 131 is used to close the opening. The two electrode assemblies 120 are stacked and housed in the mounting cavity. Two tabs 121 with opposite polarities protrude from the same end of the electrode assembly 120. The two tabs 121 are a positive electrode tab 121a and a negative electrode tab 121b, respectively.

[0170] The end cap 131 has two protrusions 1312 that arch outward toward the outer casing 110, while the remaining non-arched portion forms the body 1311. Each protrusion 1312 has a receiving groove on the side facing the electrode assembly 120. The two protrusions 1312 are spaced apart along the length of the casing 140. The protrusions 1312 smoothly transition into the body 1311, and are waist-shaped. Two circular mounting holes 13121 are provided through each protrusion 1312.

[0171] The insulating component 136 has two arched portions 1362 extending outwards from the outer casing 110, while the remaining non-arched portion forms an insulating plate 1361. The two arched portions 1362 are spaced apart along the length of the outer casing 110. The insulating component 136 is disposed on the side of the end cap 131 facing inwards from the outer casing 110. The insulating plate 1361 is attached to the bottom surface of the body 1311. The arched portions 1362 are adapted to the protrusions 1312, and the arched portions 1362 are at least partially accommodated in the receiving grooves. The bottom surfaces of the two arched portions 1362 and the two protrusions 1312 are attached one-to-one. The arched portions 1362 have two through-holes, each of which is collinear with a mounting hole 13121, and the diameter of the opening is smaller than the diameter of the mounting hole 13121.

[0172] Two electrode units 132 correspond one-to-one with two protrusions 1312. Each electrode unit 132 includes a first limiting member 1321, a second limiting member 1323, and two pole posts 1322. The shape of the first limiting member 1321 is adapted to the shape of the arched portion 1362. The first limiting member 1321 is located on the side of the arched portion 1362 facing away from the protrusions 1312. The first limiting member 1321 is at least partially accommodated in the receiving groove. The first limiting member 1321 has two through holes, each of which is collinear with a mounting hole 13121. The shape of the second limiting member 1323 is adapted to the shape of the protrusion 1312. The second limiting member 1323 is located on the side of the protrusion 1312 facing away from the arched portion 1362, that is, the protrusion 1312 is located between the second limiting member 1323 and the arched portion 1362, and the arched portion 1362 is located between the protrusion 1312 and the first limiting member 1321. The top end of the pole post 1322 is integrally formed with the second limiting member 1323. The pole post 1322 passes through the mounting hole 13121 and the opening from top to bottom, and then extends into the through hole and is riveted to the through hole. That is, the bottom end of the pole post 1322 is riveted to the first limiting member 1321. The bottom surface of the first limiting member 1321 is flush with the bottom surface of the insulating plate 1361 and the axial end face of the bottom end of the pole post 1322. The top surface of the second limiting member 1323 is recessed to form two first positioning holes 1324, and the two first positioning holes 1324 are coaxially arranged in a one-to-one correspondence with the two pole posts 1322.

[0173] One electrode unit 132's first limiting member 1321 is welded to the positive electrode tabs 121a of the two electrode assemblies 120 via a first welding portion 133, and the other electrode unit 132's first limiting member 1321 is welded to the negative electrode tabs 121b of the two electrode assemblies 120 via the first welding portion 133. The maximum weld depth of the first welding portion 133 on the first limiting member 1321 is 2mm. Figure 9 As shown, the first welding part 133 is rectangular in the welding area on the bottom surface of the first limiting member 1321 and is located between two through holes.

[0174] Each electrode unit 132's second limiting member 1323 is welded to the busbar component via two second welding portions 134. The welding areas of the two second welding portions 134 on the top surface of the second limiting member 1323 are both circular, and the centers of the welding areas of the two second welding portions 134 on the top surface of the second limiting member 1323 are concentric with the two first positioning holes 1324, corresponding one-to-one. The maximum welding depth of the second welding portion 134 on the second limiting member 1323 is 3 mm, and the minimum thickness h of the electrode unit 132 is 5 mm.

[0175] An exemplary assembly process for the battery cell 11 in this embodiment may be as follows: An end cap 131 and a terminal assembly are provided. The terminal assembly is pre-formed using an integral molding process to include a second limiting member 1323 and a terminal 1322. The terminal 1322 is passed through a mounting hole 13121 from one side of the end cap 131. A first limiting member 1321 is provided, and the first limiting member 1321 is moved to the other side of the end cap 131 so that the through hole is aligned with the terminal 1322. The first limiting member 1321 is then moved further so that the terminal 1322 passes through the through hole and is riveted to the first limiting member 1321, resulting in an end cap assembly 130. An electrode assembly 120 is provided, and the electrode assembly 120 is electrically connected to the first limiting member 1321. A housing 140 is provided, and the pre-assembled and connected electrode assembly 120 and end cap assembly 130 are installed together inside the housing 140, and the end cap 131 is connected to the housing 140 to close the opening.

[0176] 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 by, include: The outer shell has a first wall; The electrode assembly is housed within the housing; An electrode unit is disposed on the first wall and electrically connected to the electrode assembly; The first wall has a portion that arches outward toward the outer shell to form a protrusion, and the protrusion has a through mounting hole. The electrode unit includes an electrode post and a first limiting member and a second limiting member connected through the electrode post. The electrode post passes through the mounting hole. The first limiting member is at least partially disposed on the side of the first wall facing the electrode assembly, and the second limiting member is at least partially disposed on the side of the first wall away from the electrode assembly. Along the thickness direction of the first wall, both the first limiting member and the second limiting member overlap at least partially with the first wall. The protrusion has a receiving groove on the side facing the electrode assembly, and the first limiting member is at least partially received in the receiving groove.

2. The battery cell of claim 1, wherein, At least one of the first limiting member and the second limiting member is provided with a receiving portion, and the pole post is assembled and connected with the receiving portion.

3. The battery cell of claim 2, wherein, The electrode assembly is provided with tabs; The electrode unit is welded to the tab portion via a first fusion joint and to an external device via a second fusion joint; the portions of the first fusion joint on the electrode unit and the portions of the second fusion joint on the electrode unit do not overlap.

4. The battery cell of claim 3, wherein, The electrode unit has a first end face and a second end face facing away from each other, the first end face facing the inside of the housing and the second end face facing the outside of the housing; The first limiting member is welded to the electrode ear to form the first welded part. The orthographic projection of the center of the welded area formed by the first welded part on the first end face onto the target plane does not fall within the orthographic projection of the electrode on the target plane. The orthographic projection of the center of the welded area formed by the second welded part on the second end face onto the target plane falls within the orthographic projection of the electrode on the target plane. The target plane is perpendicular to the thickness direction of the first wall.

5. The battery cell of claim 4, wherein, The second limiting member is integrally formed with the pole post, or the second limiting member is provided with the receiving portion and the receiving portion is a blind hole; The second end face is recessed to form a first positioning hole, each of the first positioning holes is coaxially arranged with one of the pole posts, and the center of the welding area formed by each second welding part on the second end face coincides with the center of one of the first positioning holes.

6. The battery cell of claim 4, wherein, The first limiting member is provided with the receiving portion and the receiving portion is a through hole, and there are two through holes; the first limiting member is welded to the electrode ear to form a first fusion portion, and the fusion area formed by the first fusion portion on the first end face is located between the two through holes.

7. The battery cell according to any one of claims 4 to 6, characterized in that, In the direction perpendicular to the thickness of the first wall, the welding area formed by the first welded portion on the first end face is offset from the welding area formed by the second welded portion on the second end face.

8. The battery cell according to any one of claims 4 to 6, characterized in that, The welding area formed by the first welding portion on the first end face and the welding area formed by the second welding portion on the second end face at least partially coincide on the orthographic projection of the target plane, and the target plane is perpendicular to the thickness direction of the first wall; The normal distance between the first end face and the second end face is h; the weld depth H1 of the first welded portion in the electrode unit is within a first preset range, and the weld depth H2 of the second welded portion in the electrode unit is within a second preset range, where the maximum value H1 of the first preset range is... MAX The maximum value H2 of the second preset range interval MAX The sum of them equals h.

9. The battery cell of claim 8, wherein, H1 MAX is 2 mm, H2 MAX is 3 mm.

10. The battery cell according to any one of claims 2 to 9, characterized in that, The electrode post includes a first segment and a second segment connected sequentially along the thickness direction of the first wall. The first segment is connected to the second limiting member, and the second segment is located on the side of the protrusion facing the electrode assembly. The second segment cooperates with the receiving portion.

11. The battery cell of any one of claims 1 to 10, wherein, The protrusion is provided with a plurality of mounting holes, and the electrode unit is provided with a plurality of electrode posts corresponding one-to-one with the plurality of mounting holes.

12. The battery cell of any one of claims 1 to 11, wherein, The housing includes a shell and an end cap assembly, the shell having an opening and the end cap assembly for closing the opening; The end cap assembly includes an end cap and an insulating member. The end cap serves as the first wall. The insulating member is disposed on the side of the end cap facing the inside of the housing. A portion of the insulating member is arched outward toward the outside of the housing to form an arched portion. The arched portion is at least partially accommodated in the receiving groove. The arched portion is provided with an opening. The pole post is also disposed through the opening. A portion of the arched portion is sandwiched between the first limiting member and the protrusion.

13. The battery cell of claim 12, wherein, The orthographic projection of the mounting hole onto the arched portion along its own through-path completely covers the opening.

14. The battery cell according to claim 12 or 13, characterized in that, The body on the end cap located around the protrusion and the insulating plate on the insulating member located around the arch are attached to each other, and the first end face of the electrode unit facing into the housing is flush with the side of the insulating plate facing away from the body.

15. The battery cell of any one of claims 1 to 14, wherein, The protrusion arches outward from the body located around the protrusion on the first wall toward the outer shell, and the protrusion transitions smoothly with the body.

16. A battery device characterized by comprising: Includes the battery cell as described in any one of claims 1 to 15.

17. An electrical device, characterized by The electrical device includes a battery cell as described in any one of claims 1 to 15, or the electrical device includes a battery device as described in claim 16.

18. An energy storage device, characterized by, The energy storage device includes a single battery cell as described in any one of claims 1 to 15, or the energy storage device includes a battery device as described in claim 16.

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