Battery cell and system for its manufacture, battery and electrical device

Abstract

A battery cell, comprising: a housing with an opening attached; an electrode arrangement housed within the casing; and an end cap configured to fit and cover the opening, the end cap comprising a cap body and a section projecting around the cap body, the projecting section extending from an inner surface of the cap body towards the electrode arrangement, and at least a portion of the projecting section being arranged in the housing and configured to fit into the housing, wherein a recessed section is formed on the end cap at a position corresponding to the protruding section, and the recessed section extends from an outer surface of the cap body towards the electrode arrangement and is configured to dissipate stress while the protruding section extends into the housing.

Description

TECHNICAL AREA

[0001] The present application relates to the technical field of batteries, in particular a battery cell and a system for its manufacture, a battery and an electrical device. BACKGROUND

[0002] Battery cells are commonly used in electronic devices such as mobile phones, laptops, electric transport carts, electric vehicles, electric aircraft, electric boats, electric toy cars, electric toy ships, electric toy airplanes, and power tools. Battery cells can include nickel-cadmium batteries, nickel-hydrogen batteries, lithium-ion batteries, secondary alkaline zinc-manganese batteries, and the like.

[0003] In the development of battery technology, the question of how to improve the efficiency of battery cell assembly is a research topic in battery technology. SUMMARY

[0004] The present application relates to a battery cell and a system for its manufacture, a battery and an electrical device for improving the assembly efficiency of the battery cell and increasing the safety of the battery cell.

[0005] According to a first aspect, an embodiment of the present application provides a battery cell comprising the following: a housing with an opening attached; an electrode arrangement housed within the casing; and an end cap configured to fit and cover the opening, the end cap comprising a cap body and a section projecting around the cap body, the projecting section extending from an inner surface of the cap body towards the electrode arrangement, and at least a portion of the projecting section being arranged in the housing and configured to fit into the housing, wherein a recessed section is formed on the end cap at a position corresponding to the protruding section, and the recessed section extends from an outer surface of the cap body towards the electrode arrangement and is configured to dissipate stress while the protruding section extends into the housing.

[0006] In the above solution, during the end cap fitting process, the protruding section can extend into the housing and engage with it to limit the end cap's position. This reduces the difficulty of positioning the housing and end cap and improves battery cell assembly efficiency. The housing can limit the end cap's position using the protruding section. This reduces offset and misalignment between the end cap and housing during the joining process and improves sealing performance. The recessed section reduces the strength of the protruding section.In this way, when the protruding section and the housing press against each other, the stress can be relieved by deformation, reducing the extrusion force and friction between the protruding section and the housing, reducing the particles produced, decreasing the risk of deformation of the housing, and improving the safety of the battery cell.

[0007] In some embodiments, in one thickness direction of the end cap, a bottom surface of the recessed section is closer to the electrode arrangement than the entire inner surface of the cap body.

[0008] The aforementioned technical solution ensures sufficient depth of the first recessed section to increase the amount by which the protruding section extends beyond the inner surface of the cap body. This improves the fit between the protruding section and the housing and increases the elasticity of the protruding section, thereby reducing the extrusion force and friction between the protruding section and the housing. This, in turn, reduces the amount of particles generated, decreases the risk of housing deformation, and improves the safety performance of the battery cell.

[0009] In some embodiments, a side wall of the housing extends along a thickness direction of the end cap and is arranged around the electrode assembly, and an inner wall surface of the side wall and an outer circumferential surface of the protruding section are both arranged parallel to the thickness direction and opposite each other.

[0010] In the above technical solution, the inner wall surface of the side wall runs parallel to the outer circumferential surface of the projecting section. In this way, when the inner wall surface of the side wall and the outer circumferential surface of the projecting section come into contact and press against each other, the force exerted between the inner wall surface of the side wall and the outer circumferential surface of the projecting section is distributed relatively evenly, thereby reducing the stress concentration and the deformation of the housing and the projecting section.

[0011] In some embodiments, the side wall of the housing is press-fitted with the protruding section, so that the inner wall surface of the side wall rests against the outer circumferential surface of the protruding section.

[0012] In the above solution, the press fit increases the bond strength between the housing and the end cap and improves sealing performance. In this design, the strength of the protruding section is reduced by the recessed section, thus decreasing the force exerted between the protruding section and the housing as the protruding section extends into the housing. In this way, even with a press fit between the housing and the protruding section, particle generation is reduced, the risk of housing deformation is minimized, and the safety performance of the battery cell is improved.

[0013] In some embodiments, the inner wall surface of the side wall is welded to the outer circumferential surface of the projecting section to form a first weld section. In the thickness direction extending away from the electrode arrangement, the first weld section does not project beyond the outer surface of the cap body.

[0014] In the above solution, the cap body can serve as the supporting structure for the battery cell. After the battery cell is installed in an electrical device, an external support structure can support the battery cell through the cap body. In this design, the first weld section does not protrude beyond the outer surface of the cap body in the direction away from the electrode assembly. This reduces the force between the external support structure and the first weld section, decreases the risk of first weld section breakage, and ensures high bond strength and sealing performance between the housing and the end cap.

[0015] In some embodiments, the side wall comprises a first outer end face around the opening, and this first outer end face is connected to the inner wall surface of the side wall. In the thickness direction, the projecting section comprises a second outer end face at an end facing away from the electrode assembly. The second outer end face is connected to the outer circumferential surface of the projecting section. The first outer end face is flush with the second outer end face. The first outer end face and the second outer end face are closer to the electrode assembly than the outer surface of the cap body.

[0016] The above technical solution ensures that the first outer end face and the second outer end face are located closer to the electrode assembly than the outer surface of the cap body. This prevents the first weld section from extending beyond the first and second outer end faces, even if it protrudes beyond them, and prevents it from extending beyond the outer surface of the cap body in the direction away from the electrode assembly. This reduces the force exerted on the first weld section, minimizes the risk of breakage, and ensures high joint strength and sealing performance between the housing and the end cap.

[0017] In some embodiments, the housing also includes a flanged section. The flanged section is connected to the side wall and bent against the side wall in the direction of the cap body to cover the first welded section.

[0018] In the above technical solution, the flange section can protect the first weld section, reduce the risk of corrosion and damage to the first weld section, and ensure high joint strength and sealing performance between the housing and the end cap.

[0019] In some embodiments, the end cap additionally comprises an extension section that projects beyond the outer circumferential surface of the projecting section and surrounds it. An inner surface of the extension section is welded to a first outer end face of the side wall around the opening, so that the housing and the end cap are joined as a single piece.

[0020] In the above technical solution, the first outer end face in a process for fitting the end cap to the housing serves to limit the position of the end cap in the thickness direction, thereby reducing the risk of over-inserting the end cap into the housing and improving the efficiency of the assembly.

[0021] In some embodiments, the protruding section is in clearance fitting with the housing to form a clearance between the outer circumferential surface of the protruding section and the inner wall surface of the side wall.

[0022] In the above technical solution, the clearance fit not only ensures proper limitation of the position of the protruding section by the housing, but also reduces the force exerted between the protruding section and the housing as the protruding section extends into the housing, thereby reducing the risk of friction between the protruding section and the housing, reducing the particles generated, reducing the deformation of the housing, and improving the safety performance of the battery cell.

[0023] In some embodiments, the gap between the outer circumferential surface of the protruding section and the inner wall surface of the side wall in a direction pointing from the electrode arrangement to the side wall is 0.02 mm to 0.5 mm.

[0024] In the aforementioned technical solution, the risk of friction between the outer circumferential surface of the protruding section and the inner wall surface of the side wall increases with the size of the gap, and the risk of particle formation is correspondingly higher. Conversely, the larger the gap, the greater the area in which the protruding section is movable after extending into the housing, and the greater the risk of a poor weld between the extension section and the housing. To mitigate this risk and improve safety, the inventor specifies a gap size of 0.02 mm to 0.5 mm.

[0025] In some embodiments, a relief slot is arranged on the inner surface of the extension section. The relief slot is arranged around the projecting section, and a slotted wall surface of the relief slot is configured to connect the inner surface of the extension section and the outer circumferential surface of the projecting section.

[0026] In the aforementioned technical solution, a rounded corner is arranged at a junction between the protruding section and the extension section during its formation to reduce stress concentration. In this solution, a relief slot is provided on the extension section. A portion belonging to the extension section and opposite the relief slot is connected to the protruding section. The relief slot is recessed to provide a flow channel for material from the protruding section during its formation. This creates the rounded corner on the portion belonging to the extension section and opposite the relief slot. The rounded surface forms part of the diaphragm wall surface of the relief slot. The diaphragm wall surface is recessed relative to the inner surface of the extension section.Therefore, this embodiment ensures that the first outer end face lies smoothly against the inner surface of the extension section to prevent the rounded corner from coming into contact with the first outer end face.

[0027] In some embodiments, an outer surface of the extension section is flush with the outer surface of the cap body.

[0028] In the above technical solution, the external support structure can support the battery cell via the extension section and the cap body, thereby increasing the area of ​​the load-bearing part of the end cap and increasing the stability of the battery cell.

[0029] In some embodiments, the extension section does not extend beyond an outer surface of the side wall in a direction pointing from the electrode arrangement to the side wall.

[0030] The aforementioned technical solution prevents the extension section from increasing the maximum size of the battery cell and ensures a high energy density of the battery cell. Furthermore, the end cap is relatively thin. The extension section could scratch other external components if it protrudes beyond the outer surface of the side wall.

[0031] In some embodiments, the outer wall surface of the side wall extends from the electrode arrangement to the side wall by 0.02 mm to 0.5 mm beyond the extension section.

[0032] In the aforementioned technical solution, the risk of the second weld section, formed by welding between the side wall and the extension section, protruding beyond the outer surface of the side wall increases the smaller the amount by which the outer surface of the side wall protrudes beyond the extension section. The larger the amount by which the outer surface of the side wall protrudes beyond the extension section, the smaller the contact area between the extension section and the side wall, and the lower the bond strength between the extension section and the side wall. The inventor sets the amount by which the outer surface of the side wall protrudes beyond the extension section to between 0.02 mm and 0.5 mm, thus minimizing the risk of the second weld section protruding beyond the outer surface of the side wall, provided that a high bond strength is achieved.

[0033] In some embodiments, in the direction pointing from the electrode arrangement to the side wall, the amount by which the extension section extends beyond the outer circumferential surface of the protruding section is less than the wall thickness of the side wall.

[0034] In the above solution, the outer wall surface of the side wall projects beyond the extension section in the direction of the side wall from the electrode arrangement when the outer circumferential surface of the projecting section abuts the inner wall surface of the side wall, since the wall thickness of the side wall is greater than the amount by which the extension section projects beyond the outer circumferential surface of the projecting section.

[0035] In some embodiments, the protruding section further comprises a guide surface facing the side wall. The guide surface is connected to an end that forms the outer circumferential surface of the protruding section and is located near the electrode assembly. The guide surface slopes away from the inner wall surface of the side wall toward the outer circumferential surface of the protruding section in order to guide the protruding section so that it extends into the housing.

[0036] In the above technical solution, by arranging a tilting guide surface on the protruding section, the protruding section can be guided into the housing during a process for fitting the end cap to the housing, thereby simplifying the assembly process and improving assembly efficiency.

[0037] In some embodiments, the foreground section abuts a first tab of the electrode arrangement to support the first tab.

[0038] In the above solution, the preceding section can support the first tab, thereby reducing the vibration amplitude of the electrode assembly during vibration of the battery cell and improving the stability of the electrode assembly.

[0039] In some embodiments, the protruding section is welded to the first tab in order to electrically connect the first tab and the end cap.

[0040] In the aforementioned technical solution, the protruding section is welded directly to the first tab without the need for additional adapters, thus simplifying the battery cell structure. This solution also reduces the thickness of the protruding section by means of the recessed section, thereby decreasing the welding power required to weld the protruding section to the first tab, reducing heat dissipation, and minimizing the risk of burning other components.

[0041] In some embodiments, the first tab of the electrode assembly is electrically connected to the housing via the end cap.

[0042] In the described technical solution, the housing is connected to the first tab of the electrode assembly via the end cap, so that the potential of the housing essentially corresponds to the potential of the first tab. In this way, the housing itself can serve as the output electrode of the battery cell, thus eliminating the need for a conventional electrode connection and simplifying the battery cell structure. When multiple battery cells are grouped together, the housing can be electrically connected to a busbar component, thereby not only increasing the through-area but also allowing for greater flexibility in the structural design of the busbar component.

[0043] In some embodiments, the housing comprises a side wall and a bottom wall. The side wall extends along a thickness direction of the end cap and is arranged around the electrode assembly. The bottom wall is connected to one end of the side wall and is located on the side of the electrode assembly facing away from the end cap. An electrode exit opening is provided on the bottom wall. A second tab is provided on the electrode assembly at an end facing the bottom wall, and the first and second tabs have opposite polarities. The battery cell further comprises an electrode terminal that is located in the electrode exit opening, and the electrode terminal is electrically connected to the second tab.

[0044] In the above solution, the bottom wall and the electrode terminal can serve as two output electrodes of the battery cell, thus simplifying the battery cell structure and ensuring high current carrying capacity. The bottom wall and the electrode terminal are located at the same end of the battery cell. This allows the busbar component to be mounted on the same side of the battery cell, simplifying the assembly process and improving efficiency when assembling large numbers of battery cells into groups.

[0045] In some embodiments, the bottom wall and the side wall form a single structure.

[0046] The above technical solution avoids the step of connecting the bottom wall and the side wall and reduces the resistance between the bottom wall and the side wall.

[0047] In some embodiments, the first tab is a negative tab, and a support material of the housing is steel.

[0048] In the above technical solution, the housing is electrically connected to the negative terminal. This means the housing is in a low-potential state. The steel housing in this low-potential state is resistant to corrosion from electrolyte solutions, thus reducing safety risks.

[0049] In some embodiments, the battery cell is a cylindrical cell.

[0050] According to a second aspect, an embodiment of the present application provides a battery comprising a plurality of battery cells according to any embodiment of the first aspect.

[0051] According to a third aspect, an embodiment of the present application provides an electrical device comprising the battery according to the second aspect. The battery is configured to supply electrical energy.

[0052] According to a fourth aspect, one embodiment provides a method for manufacturing a battery cell which includes the following: Providing a housing, wherein the housing has an opening; Providing an electrode assembly and installing the electrode assembly in the housing; Providing an end cap, wherein the end cap comprises a cap body and a section projecting around the cap body, the projecting section being directed from an inner surface of the cap body, wherein a recessed section is formed on the end cap at a position corresponding to the projecting section and the recessed section is recessed from an outer surface of the cap body; Extend at least part of the preceding section into the housing in order to fit into the housing; and Connecting the end cap to the housing so that the end cap fits onto the opening and covers it, whereby The protruding section extends from an inner surface of the cap body towards the electrode assembly, the recessed section is recessed from an outer surface of the cap body towards the electrode assembly, and the recessed section is configured to dissipate stress while the protruding section extends into the housing.

[0053] According to a fifth aspect, an embodiment of the present application provides a system for manufacturing a battery cell comprising the following: a first provisioning device configured to provide a housing, the housing having an opening formed; a second staging device configured to stag an electrode assembly and mount the electrode assembly in the housing; a third provisioning device configured to provide an end cap, the end cap comprising a cap body and a projecting section around the cap body, the projecting section extending from an inner surface of the cap body, a recessed section on the end cap being formed at a position corresponding to the projecting section, and the recessed section being recessed from an outer surface of the cap body; a first mounting device configured such that at least part of the protruding section projects into the housing in order to fit into the housing; and a second mounting device configured to connect the end cap and the housing so that the end cap fits the opening and covers it, wherein The protruding section extends from an inner surface of the cap body towards the electrode arrangement, the recessed section extends from an outer surface of the cap body towards the electrode arrangement, and the recessed section is configured to dissipate stress while the protruding section extends into the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] To more clearly describe the technical solutions in the embodiments of the present application, the drawings used in these embodiments are described below. The drawings shown below are merely examples of embodiments of the present application. A person with average technical knowledge can derive further drawings from the sketched drawings without any creative effort. Fig. Figure 1 is a schematic structural diagram of a vehicle according to some embodiments of the present application. Fig. 2 is a schematic exploded view of a battery according to some embodiments of the present application; Fig. 3 is a schematic exploded view of the in Fig. 2 battery modules shown. Fig. Figure 4 is a schematic exploded view of a battery cell according to some embodiments of the present application; Fig. Figure 5 is a schematic sectional view of a battery cell according to some embodiments of the present application. Fig. 6 is a detailed view of a circled position A of the in Fig. 5. Fig. Figure 7 is a schematic sectional view of a battery cell according to further embodiments of the present application. Fig. Figure 8 is a schematic sectional view of a battery cell according to a further embodiment of the present application. Fig. 9 is a detailed view of a circled position B of the in Fig. 8 battery cells shown; Fig. 10 is a detailed view of a rectangular position C, which is in Fig. 9 is shown. Fig. Figure 11 is a schematic flowchart of a process for manufacturing a battery cell; and Fig. Figure 12 is a schematic block diagram of a system for manufacturing a battery cell according to some embodiments of the present application.

[0055] The drawings are not to scale. DETAILED DESCRIPTION OF THE EXECUTION FORMS

[0056] To clarify the objectives, technical solutions, and advantages of the embodiments of the present application, the technical solutions in the embodiments of the present application are described below with reference to the drawings in those embodiments. It is evident that the described embodiments represent only a part, but not all, of the embodiments of the present application. All other embodiments that a person with average expertise in this field could derive from the embodiments of the present application without creative effort fall within the scope of protection of the present application.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as they are generally understood by a person skilled in the art in the field of the present application. The terms used in the description of the present application serve only to describe specific embodiments and do not constitute a limitation of the present application. The terms "comprise" and "include," and all variants thereof, used in the description, claims, and short description of the drawings of the present application, are to be understood as non-exclusive inclusions. The terms "first" and "second," used in the description, claims, and short description of the drawings, serve to distinguish between different elements but do not describe any particular order or precedence.

[0058] The reference to "embodiment" in the present application means that a specific feature, structure, or property described with reference to the embodiment may be included in at least one embodiment of the present application.

[0059] In the description of this application, the terms "assemble," "link," "connect," and "attach" are to be understood in a broad sense unless expressly stated and defined otherwise. A "connection," for example, may be a permanent connection, a detachable connection, or an integrated connection; it may be a direct connection or an indirect connection established via an intermediary; or it may be internal communication between two components. A person with average technical knowledge will understand the specific meanings of the terms in this application according to the context.

[0060] The term “and / or” in this application merely denotes a relationship for describing the associated elements and represents three possible relationships. For example, “A and / or B” can represent the following three circumstances: A alone, A and B together, and B alone. Furthermore, the symbol “ / ” in this document generally denotes an “or” relationship between the element preceding the symbol and the element following the symbol.

[0061] In embodiments of the present application, the same reference numeral denotes the same component. For the sake of brevity, detailed descriptions of the same component in another embodiment are omitted. It is understood that dimensions such as thickness, length, and width of various components in the embodiments of the present application shown in the drawings, as well as dimensions such as overall thickness, overall length, and overall width of an integrated device, are merely illustrative descriptions and do not constitute a limitation of the present application.

[0062] The term ‘a plurality of’ used in the present application means two or more (including two).

[0063] In the present application, a battery cell may comprise a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, a magnesium-ion battery cell, or the like. The embodiments of the present application do not restrict the type of battery cell. The battery cell may have a cylindrical shape, a flat shape, a cuboid shape, or other shapes, without this being limited to embodiments of the present application.

[0064] The battery mentioned in the embodiments of the present application refers to a self-contained physical module containing one or more battery cells to provide a higher voltage and capacity. For example, the battery mentioned in the present application may comprise a battery module, a battery pack, or the like. A battery typically includes a housing designed to accommodate one or more battery cells. The housing prevents liquids or other foreign matter from interfering with the charging or discharging of the battery cells.

[0065] A battery cell comprises an electrode assembly and an electrolyte solution. The electrode assembly includes a positive electrode plate, a negative electrode plate, and a separator. The battery cell primarily functions by the transport of metal ions between the positive and negative electrode plates. The positive electrode plate includes a positive current collector and a positive active material layer. The positive active material layer is applied to a surface of the positive current collector. The positive current collector includes a positive current collector section and a positive tab connected to the positive current collector section. The positive current collector section is coated with a layer of positive active material. The positive tab is not coated with the positive active material layer. In the case of a lithium-ion battery, the positive current collector can be made of aluminum.The positive active material layer comprises a positive active material. The positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, lithium manganese oxide, or the like. The negative electrode plate comprises a negative current collector and a negative active material layer. The negative active material layer is applied to a surface of the negative current collector. The negative current collector comprises a negative current collecting section and a negative tab connected to the negative current collecting section. The negative current collecting section is coated with a layer of negative active material. The negative tab is not coated with the negative active material layer. The negative current collector can be made of copper. The negative active material layer comprises a negative active material. The negative active material can be carbon, silicon, or the like.The separator can be made from a material such as PP (polypropylene) or PE (polyethylene).

[0066] The battery cell also includes a housing and an end cap. An opening is provided in the housing, which is configured to accommodate the electrode assembly. The electrode assembly can be installed into the housing through this opening. The end cap is configured to fit onto and cover the housing opening to ensure a seal.

[0067] In the existing technology, the process for fitting the end cap to the housing typically requires pressing the end cap against the open end of the housing, and then joining the end cap to the housing by welding or other means. However, the inventor has found that in a process where the end cap is pressed against the housing, the housing and end cap cannot constrain each other's position. This makes positioning the housing and end cap by a fixture more difficult and reduces the assembly efficiency of the battery cell. Furthermore, misalignment and offset between the end cap and the housing can easily occur during the joining process, impairing the sealing performance.

[0068] As the inventor has determined through investigations, a protruding section can be provided on the end cap. During a process for fitting the end cap to the housing, the protruding section can be inserted into the housing and conform to the housing to limit the position of the end cap. The protruding section facilitates the positioning of the housing and the end cap, increases the assembly efficiency of the battery cell, reduces offset and misalignment between the end cap and the housing when joining the end cap and the housing, and improves sealing performance.

[0069] The inventor further discovered, however, that when inserted into the housing, the protruding section can compress the inner surface of the housing. The protruding section and the housing rub against each other, forming particles. These particles can fall into the electrode assembly and create an electrical conductor between the positive and negative electrode plates, potentially leading to safety issues. Additionally, if the pressure between the protruding section and the housing is too great, the housing can deform, affecting its appearance and compromising the airtightness of the battery cell.

[0070] Against this background, one embodiment of the present application offers a technical solution. By forming a first recessed section on the end cap at a position corresponding to the protruding section, the stress is relieved in this application as the protruding section extends into the housing. The first recessed section reduces the strength of the protruding section. In this way, when the protruding section presses against the inner surface of the housing, it can relieve the stress by deformation, reduce the extrusion force and friction between the protruding section and the housing, reduce the particles generated, decrease the risk of housing deformation, and improve the safety performance of the battery cell.

[0071] The technical solution described in this embodiment of the present application is applicable to a battery and an electrical device that uses the battery.

[0072] The electrical device can be a vehicle, mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, power tool, or the like. The vehicle can be an oil-powered vehicle, a natural gas vehicle, or a new energy vehicle. The new energy vehicle can be a battery-electric vehicle, a hybrid electric vehicle, an electric vehicle with extended range, or a similar vehicle. The spacecraft includes an aircraft, rocket, space shuttle, spacecraft, and the like. The electric toy includes a stationary or mobile electric toy, such as a game console, an electric toy car, an electric toy ship, an electric toy airplane, and the like.The power tool comprises an electric metal cutting tool, an electric grinding tool, an electric assembly tool, and a power tool for use in rail transport. Examples of power tools are an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an electric impact drill, a concrete vibrator, an electric planer, and the like. Embodiments of the present application do not specifically restrict the power tool.

[0073] To simplify the description in the following embodiments, a vehicle is used as an example for the electrical device.

[0074] Fig. Figure 1 is a schematic structural diagram of a vehicle according to some embodiments of the present application.

[0075] As in Fig. As shown in Figure 1, a battery 2 is located inside the vehicle 1. The battery 2 can be located at the bottom, front, or rear of the vehicle 1. The battery 2 can be configured to supply power to the vehicle 1. For example, the battery 2 can serve as the operating power supply for the vehicle 1.

[0076] The vehicle 1 may further comprise a control unit 3 and a motor 4. The control unit 3 is configured to control the battery 2 so that it supplies power to the motor 4, for example to start or control the vehicle 1 or to meet the vehicle's operating power requirements during operation.

[0077] In some embodiments of the present application, the battery 2 not only serves as the operating power supply of the vehicle 1, but can also serve as the drive power supply of the vehicle 1 in order to provide drive energy for the vehicle 1 instead of or partially instead of oil or natural gas.

[0078] Fig. Figure 2 is a schematic exploded view of a battery according to some embodiments of the present application.

[0079] As in Fig. As shown in Figure 2, the battery 2 comprises a housing 5 and a battery cell (in Fig. 2 (not shown). The battery cell is housed in casing 5.

[0080] The housing 5 is configured to accommodate the battery cell. The housing 5 can have various structures. In some embodiments, the housing 5 can comprise a first housing part 5a and a second housing part 5b. The first housing part 5a and the second housing part 5b fit inside each other and cover each other. The first housing part 5a and the second housing part 5b together define a receiving space 5c configured to receive the battery cell. The second housing part 5b can be a hollowed-out structure open at one end. The first housing part 5a is a plate-like structure. The first housing part 5a fits onto the open side of the second housing part 5b to form the housing 5 containing the receiving space 5c. The first housing part 5a and the second housing part 5b can each have a hollowed-out structure open at one end.The open end of the first housing part 5a fits onto the open end of the second housing part 5b, thus forming the housing 5 with the receiving chamber 5c. Naturally, the first housing part 5a and the second housing part 5b can have different shapes, for example, a cylinder or a cuboid.

[0081] To improve the airtightness between the first housing part 5a and the second housing part 5b, which are connected to each other, a sealing element such as a sealant or a sealing ring can be arranged between the first housing part 5a and the second housing part 5b.

[0082] Assuming that the first housing part 5a fits on top of the second housing part 5b, the first housing part 5a can also be referred to as the upper housing and the second housing part 5b as the lower housing.

[0083] The battery 2 can contain one or more battery cells. If a plurality of battery cells is present, the plurality of battery cells can be connected in series, parallel, or series-parallel. The series-parallel connection pattern refers to a combination of series and parallel connection of the plurality of battery cells. The plurality of battery cells can be connected directly in series, parallel, or series-parallel, and then the entire plurality of battery cells can be housed in the casing 5. Alternatively, the plurality of battery cells can be connected in series, parallel, or series-parallel to form a battery module 6, and then a plurality of battery modules 6 are connected in series, parallel, or series-parallel to form a whole that can be housed in the casing 5.

[0084] Fig. 3 is a schematic exploded view of the in Fig. 2 battery modules shown.

[0085] In some embodiments, such as in Fig. As shown in Figure 3, there is a plurality of battery cells 7. The plurality of battery cells 7 are connected in series, parallel, or series-parallel to initially form a battery module 6. A plurality of battery modules 6 are then connected in series, parallel, or series-parallel to form a whole that can be housed in the casing.

[0086] The multitude of battery cells 7 in the battery module 6 can be electrically connected by a busbar component to realize a parallel circuit, a series circuit or a series-and-parallel circuit between the multitude of battery cells 7 in the battery module 6.

[0087] Fig. Figure 4 is a schematic exploded view of a battery cell according to some embodiments of the present application; Fig. 5 is a schematic sectional view of a battery cell according to some embodiments of the present application; and Fig. 6 is a detailed view of a circled position A of the in Fig. 5 battery cells shown.

[0088] As in Fig. 4 to Fig. As shown in Figure 6, the battery cell 7 according to an embodiment of the present application comprises: a housing 20 having an opening 21; an electrode arrangement 10 housed in the housing 20; and an end cap 30 configured to fit onto and cover the opening 21. The end cap 30 comprises a cap body 31 and a projecting section 32 surrounding the cap body 31. The projecting section 32 extends from an inner surface 311 of the cap body toward the electrode arrangement 10. At least a portion of the projecting section 32 is located within the housing 20 and is configured to fit into the housing 20. A recessed section 33 is formed on the end cap 30 at a position corresponding to the projecting section 32.The recessed section 33 is recessed from an outer surface 312 of the cap body in the direction of the electrode arrangement 10 and is configured to dissipate stress, while the projecting section 32 extends into the housing 20.

[0089] The electrode arrangement 10 comprises a first electrode plate, a second electrode plate, and a separator. The separator is configured to separate the first electrode plate from the second electrode plate. The first and second electrode plates are oppositely polarized. In other words, one of the first or second electrode plates is a positive electrode plate, and the other of the first or second electrode plate is a negative electrode plate.

[0090] Optionally, the first electrode plate, the second electrode plate, and the separator can all have ribbon-like structures. The first electrode plate, the second electrode plate, and the separator are wound together to form a jelly roll structure. The jelly roll structure can be cylindrical, flat, or have another shape.

[0091] The housing 20 is a hollowed-out structure that is open at one end. The end cap 30 fits onto the opening of the housing 20 and is hermetically sealed to it to form a receiving chamber designed to hold the electrode assembly 10 and the electrolyte solution.

[0092] The housing 20 is a structure that is hollowed out to form a space configured to receive the electrode assembly 10. The housing 20 can have various shapes, such as a cylinder or a cuboid. The shape of the housing 20 can be determined depending on the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 has a cylindrical structure, the housing can be cylindrical. If the electrode assembly 10 has a cuboid structure, the housing can be cuboid.

[0093] The housing 20 can be positively charged, negatively charged, or uncharged. To charge the housing 20, it can be directly connected to the electrode plate of the electrode assembly 10 or electrically connected to the electrode plate via other conductive elements.

[0094] Optionally, the end cap 30 and the housing 20 can be joined by welding, so that the end cap 30 and the housing 20 essentially have the same potential. For example: To positively charge the housing 20, the housing 20 can be electrically connected to the positive electrode plate using the end cap 30. To negatively charge the housing 20, the housing 20 can be electrically connected to the negative electrode plate using the end cap 30. Of course, the housing 20 can also be connected to the electrode plate by other conductive structures, without this being limited to this embodiment.

[0095] The end cap 30 can be electrically connected to the electrode assembly 10 or insulated from it. Optionally, the end cap 30 is electrically connected to the first electrode plate. Of course, the end cap 30 can also be directly electrically connected to the first electrode plate or electrically connected to it via other elements.

[0096] The housing 20 and the end cap 30 can be made of the same material or of different materials.

[0097] The cap body 31 is a plate-like structure comprising an inner surface and an outer surface arranged opposite each other along the thickness direction Z. The inner surface 311 of the cap body faces the electrode arrangement 10. Optionally, the cap body 31 can be a flat plate. The inner surface 311 and the outer surface 312 of the cap body are both flat and parallel to each other.

[0098] The preceding section 32 is a ring-shaped structure around the cap body 31.

[0099] The protruding section 32 projects towards the electrode arrangement 10 against the inner surface 311 of the cap body, such that at least a part of the protruding section 32 projects from the inner surface 311 of the cap body. The protruding section 32 can project completely into the housing 20 or only partially into the housing 20, without being restricted in this embodiment.

[0100] The part of the preceding section 32 that projects into the housing 20 can be in interference fit, clearance fit or transition fit with the housing 20, without being restricted in this embodiment.

[0101] The position of the recessed section 33 corresponds to the position of the protruding section 32. The recessed section 33 is recessed in the direction of the electrode arrangement 10 relative to the outer surface 312 of the cap body. The recessed section 33 reduces the strength of the protruding section 32, so that the area corresponding to the protruding section 32 at the end cap 30 is more elastic.

[0102] In this embodiment, during a process for fitting the end cap 30 to the housing 20, the projecting section 32 can extend into the housing 20 and align with it to limit the position of the end cap 30. This reduces the difficulty of positioning the housing 20 and the end cap 30 and improves the assembly efficiency of the battery cell 7. The housing 20 can limit the position of the end cap 30 with the aid of the projecting section 32. In this way, offset and misalignment between the end cap 30 and the housing 20 during joining are reduced, and the sealing performance is improved. The recessed section 33 reduces the strength of the projecting section 32.In this way, when the preceding section 32 and the housing 20 are pressed against each other, the stress can be relieved by deformation, the extrusion force and friction between the preceding section 32 and the housing 20 can be reduced, the particles produced in the process can be reduced, the risk of deformation of the housing 20 can be reduced, and the safety of the battery cell 7 can be improved.

[0103] In some embodiments, in a thickness direction Z of the end cap 30, a bottom surface of the recessed section 33 is closer to the electrode arrangement 10 than the entire inner surface 311 of the cap body.

[0104] This embodiment ensures a sufficient depth of the first recessed section 33 to increase the amount by which the projecting section 32 extends beyond the inner surface 311 of the cap body. This improves the fit between the projecting section 32 and the housing 20 and increases the elasticity of the projecting section 32, thereby reducing the extrusion force and friction between the projecting section 32 and the housing 20. This, in turn, reduces the particles generated, decreases the risk of deformation of the housing 20, and improves the safety performance of the battery cell 7.

[0105] In some embodiments, the cap body 31 may have an annular flat plate structure, and the end cap 30 may further comprise a part that is surrounded by the cap body 31.

[0106] In some embodiments, the housing 20 is welded to the end cap 30. The weld not only establishes the connection between the housing 20 and the end cap 30, but also ensures airtightness.

[0107] In some embodiments, the electrode assembly 10, viewed from its appearance, comprises a body section 11, a first tab 12, and a second tab 13. The first tab 12 and the second tab 13 project from the body section 11. The first tab 12 is a portion that is not coated with the active material layer on the first electrode plate, and the second tab 13 is a portion that is not coated with the active material layer on the second electrode plate. Accordingly, one of the first tabs 12 or the second tab 13 is a positive tab, and the other is a negative tab.

[0108] The first tab 12 and the second tab 13 can each originate from the same end of the body section 11 or from two opposite ends of the body section.

[0109] For example, the first tab 12 and the second tab 13 are each arranged at opposite ends of the body section 11. In other words, the first tab 12 and the second tab 13 are each arranged at opposite ends of the electrode assembly 10. Optionally, the first tab 12 is arranged at an end of the electrode assembly 10 that faces the end cap 30. The second tab 13 is located at an end of the electrode assembly 10 that faces away from the end cap 30.

[0110] Optionally, the first tab 12 can be wound in a plurality of circles around a central axis of the electrode arrangement 10. In other words, the first tab 12 comprises a plurality of tab layers. After completion of the winding, the first tab 12 has approximately the shape of a column, and a gap remains between two adjacent tab layers. In this embodiment of the present application, the first tab 12 can be machined to reduce the gap between the tab layers and facilitate the connection between the first tab 12 and other conductive structures. For example, in this embodiment of the present application, the first tab 12 can be kneaded and flattened so that an end region, which is part of the first tab 12 and is located far from the body section 11, can be folded over and gathered.Kneading and flattening results in the formation of a compacted end face at the end located at the first tab 12 and far from the body section 11, thereby reducing the gap between the tab layers and facilitating the connection between the first tab 12 and other conductive structures. Alternatively, in this embodiment of the present application, a conductive material can fill the gap between the two adjacent tab layers to reduce the gap between the tab layers.

[0111] Optionally, the second tab 13 is wound in a plurality of circles around the central axis of the electrode arrangement 10, such that the second tab 13 comprises a plurality of tab layers. For example, the second tab 13 is also kneaded and flattened to reduce the gap between the tab layers of the second tab 13.

[0112] In some embodiments, the first tab 12 is arranged at the end that is located at the electrode assembly 10 and is oriented towards the end cap 30. The first tab 12 is electrically connected to the end cap 30.

[0113] The end cap 30 can be directly connected to the first tab 12. For example, the end cap 30 can be directly welded to the first tab 12 to establish an electrical connection between the end cap 30 and the first tab 12. Alternatively, the end cap 30 can also be indirectly connected to the first tab 12 via other conductive structures (such as a current collector element 50).

[0114] In this embodiment, the potential of the end cap 30 can essentially correspond to the potential of the first tab 12, so that the end cap 30 can serve as the output electrode of the battery cell 7, thereby saving a conventional electrode connection and simplifying the structure of the battery cell 7.

[0115] In some embodiments, the first tab 12 of the electrode arrangement 10 is electrically connected to the housing 20 via the end cap 30.

[0116] In this embodiment, the housing 20 is connected to the first tab 12 of the electrode arrangement 10 via the end cap 30, so that the potential of the housing 20 essentially corresponds to the potential of the first tab 12. In this way, the housing 20 itself can serve as the output electrode of the battery cell 7, thus eliminating the need for a conventional electrode connection and simplifying the structure of the battery cell 7. When a plurality of battery cells 7 are grouped together, the housing 20 can be electrically connected to a busbar component, thereby not only increasing the through-area but also making the structural design of the busbar component more flexible.

[0117] In some embodiments, the housing 20 comprises a side wall 22 and a bottom wall 23. The side wall 22 extends along a thickness direction Z of the end cap 30 and is arranged around the electrode assembly 10. The bottom wall 23 is connected to one end of the side wall 22 and is located on a side of the electrode assembly 10 that faces away from the end cap 30. An electrode exit opening 231 is arranged on the bottom wall 23. A second tab 13 is arranged on the electrode assembly 10 at an end facing the bottom wall 23, and the first tab 12 and the second tab 13 have opposite polarities. The battery cell 7 further comprises an electrode terminal 40, which is located in the electrode exit opening 231, and the electrode terminal 40 is electrically connected to the second tab 13.

[0118] The side wall 22 and the bottom wall 23 can have a one-piece molded structure. That is, the housing 20 is a one-piece molded element. Of course, the side wall 22 and the bottom wall 23 can also be two independent elements that are provided separately and can be joined together by welding, riveting, gluing or other methods.

[0119] The side wall 22 is a cylindrical structure. For example, the side wall 22 is a cylinder or a rectangular column. The bottom wall 23 is a plate-like structure whose shape corresponds to the shape of the side wall 22. Optionally, an opening 21 can be formed at one end of the side wall 22. The bottom wall 23 is connected to the other end of the side wall 22, which points away from the opening 21.

[0120] The second tab 13 can be directly electrically connected to the electrode connection 40 or indirectly electrically connected to the electrode connection 40 via other conductive structures.

[0121] The electrode terminal 40 is dielectrically connected to the base wall 23. The electrode terminal 40 and the base wall 23 can have different polarities. The electrode terminal 40 and the base wall 23 can each serve as two output electrodes of the battery cell 7. Optionally, the battery cell 7 also includes an insulating piece. At least part of the insulating piece is located between the base wall 23 and the electrode terminal 40 to isolate the base wall 23 from the electrode terminal 40.

[0122] If the first tab 12 is a negative tab and the second tab 13 is a positive tab, then the bottom wall 23 is a negative output electrode of battery cell 7 and the electrode terminal 40 is a positive output electrode of battery cell 7. If the first tab 12 is a positive tab and the second tab 13 is a negative tab, then the bottom wall 23 is a positive output electrode of battery cell 7 and the electrode terminal 40 is a negative output electrode of battery cell 7.

[0123] The electrode connection 40 is attached to the bottom wall 23. The electrode connection 40 can be attached as a whole to the outside of the bottom wall 23 or extend through the electrode outlet opening 231 into the interior of the housing 20.

[0124] The first tab 12 is located at the end adjacent to the electrode assembly 10 and oriented towards the end cap 30 to facilitate the electrical connection between the end cap 30 and the first tab 12. Similarly, the second tab 13 is located at the end adjacent to the electrode assembly 10 and oriented towards the bottom wall 23 to facilitate the electrical connection between the electrode terminal 40 and the second tab 13. In this embodiment of the present application, the first tab 12 and the second tab 13 are each located at opposite ends of the electrode assembly 10, thereby reducing the risk of a conductive connection between the first tab 12 and the second tab 13 and increasing the through-area of ​​both the first tab 12 and the second tab 13.

[0125] In this embodiment, the bottom wall 23 and the electrode terminal 40 can serve as two output electrodes of the battery cell 7, thereby simplifying the structure of the battery cell 7 and ensuring a high current-carrying capacity. The bottom wall 23 and the electrode terminal 40 are located at the same end of the battery cell 7. In this way, the busbar component can be mounted on the same side of the battery cell 7, simplifying the assembly process and improving the efficiency of assembling a large number of battery cells 7 into groups.

[0126] In some embodiments, the bottom wall 23 and the side wall 22 form a single-piece structure. This embodiment avoids the step of joining the bottom wall 23 and the side wall 22 and reduces the resistance between the bottom wall and the side wall. For example, the housing 20 can be formed by a stretching process.

[0127] The electrode exit opening 231 in this embodiment of the present application is produced after the housing 20 has been formed by stretching.

[0128] The inventor designed a calendered opening end of a housing such that the opening end is folded inwards to form a flange structure. This flange structure presses the end cap firmly in place. The inventor mounts the electrode terminal onto the end cap and uses the flange structure and the electrode terminal, respectively, as the two output electrodes of the battery cell. However, the larger the flange structure, the greater the risk of it warping and creasing after its formation. This warping and creasing results in an uneven surface and, when the flange structure is welded to the busbar component, a poor weld. Therefore, the size of the flange structure is relatively limited, leading to insufficient current-carrying capacity of the battery cell.

[0129] In this embodiment, an electrode exit opening 231, configured for attaching the electrode terminal 40, is formed on the bottom wall 23 using a hole-drilling process to position the positive output electrode and the negative output electrode at the end located on the battery cell 7 and oriented away from the opening 21. The bottom wall 23 is formed during the formation of the housing 20 such that the flatness of the bottom wall 23 and a high bond strength between the bottom wall 23 and the busbar component are ensured after the electrode exit opening 231 has been manufactured. At the same time, the flatness of the bottom wall 23 is not limited by the size of the bottom wall. Therefore, the size of the bottom wall 23 can be relatively large, thereby improving the current-carrying capacity of the battery cell 7.

[0130] In some embodiments, the first tab 12 is a negative tab, and a support material of the housing 20 is steel.

[0131] The housing 20 is electrically connected to the negative terminal. This means that the housing 20 is in a low potential state. The steel housing 20 in this low potential state is insensitive to corrosion caused by electrolyte solutions, thus reducing safety risks.

[0132] In some embodiments, the carrier material of the housing 20 is identical to the carrier material of the end cap 30. Optionally, both the carrier material of the housing 20 and the carrier material of the end cap 30 are made of steel.

[0133] In this embodiment, the carrier material of the housing 20 is identical to the carrier material of the end cap 30, thereby ensuring the weld strength between the housing 20 and the end cap 30 and improving the airtightness of the battery cell 7.

[0134] In some embodiments, the battery cell is a cylindrical cell. Accordingly, the electrode arrangement 10 is a cylindrical structure and the housing 20 is a cylindrical hollow structure.

[0135] In some embodiments, the preceding section 32 can directly support the first tab 12 or support the first tab 12 via other elements.

[0136] In some embodiments, the foreground section 32 abuts the first tab 12 of the electrode arrangement 10 to support the first tab 12.

[0137] In this embodiment, the preceding section 32 can support the first tab 12, thereby reducing the vibration amplitude of the electrode arrangement 10 during the vibration of the battery cell 7 and improving the stability of the electrode arrangement 10.

[0138] In some embodiments, the protruding section is welded to the first tab in order to electrically connect the first tab and the end cap.

[0139] In this embodiment, the protruding section 32 can be welded directly to the first tab 12 without the need for additional adapters, thus simplifying the structure of the battery cell 7. In this embodiment, the thickness of the protruding section 32 is reduced by the recessed section 33, thereby reducing the welding power required to weld the protruding section 32 to the first tab 12, reducing heat dissipation, and decreasing the risk of burning other components.

[0140] In some embodiments, the foreground section 32 is configured to fit into the housing 20 in order to limit the position of the end cap 30 in a radial direction.

[0141] The housing 20 has a central axis, and the side wall 22 is arranged around the central axis. The central axis of the housing 20 runs along the thickness direction Z of the end cap 30. In the description of the present application, the radial direction is a direction perpendicular to the thickness direction Z and extending through the central axis.

[0142] The radial direction specified herein is applicable to cylindrical cells. In a cylindrical cell, the electrode assembly 10 is a cylindrical structure, the housing 20 is a cylindrical, hollowed-out structure, and the end cap 30 is a round plate structure. For a cylindrical cell, the "radial direction" can be a direction of the radius of the housing 20.

[0143] Naturally, the radial direction described herein is also applicable to a prismatic cell. In a prismatic cell, the electrode arrangement 10 is a flat structure, the housing 20 is a rectangular, hollowed-out structure, and the end cap 30 is a rectangular, plate-like structure.

[0144] In some embodiments, the side wall 22 of the housing 20 extends along the thickness direction Z of the end cap 30 and is arranged around the electrode assembly 10. An inner wall surface 221 of the side wall and an outer circumferential surface 321 of the protruding section are both arranged parallel to the thickness direction Z and opposite each other.

[0145] The side wall 22 of the housing 20 comprises an inner wall surface and an outer wall surface, which are arranged opposite each other. The inner wall surface 221 of the side wall faces the electrode arrangement 10. Both the inner wall surface 221 and the outer wall surface 222 of the side wall are columnar surfaces. The inner wall surface 221 of the side wall is a curved surface formed by the parallel movement of a first generator along a predetermined path. Optionally, the inner wall surface 221 is a cylindrical surface. That is, the inner wall surface 221 of the side wall is a curved surface formed by the parallel movement of the first generator along a circular path. Optionally, the outer wall surface 222 of the side wall is also a cylindrical surface.

[0146] The outer circumferential surface 321 of the preceding section is a columnar surface. The outer circumferential surface 321 of the preceding section is a curved surface formed by the parallel movement of a second generator along a predetermined path. Optionally, the outer circumferential surface 321 of the preceding section is a cylindrical surface.

[0147] If the first generatrix is ​​parallel to the second generatrix, the outer circumferential surface 321 of the preceding section is parallel to the inner wall surface 221 of the side wall. For example, both the first generatrix and the second generatrix are straight lines parallel to the thickness direction Z.

[0148] The inner wall surface 221 of the side wall surrounds the outer circumferential surface 321 of the projecting section. In this way, after the projecting section 32 extends into the housing 20, the inner wall surface 221 of the side wall can limit the position of the end cap 30 by the outer circumferential surface 321 of the projecting section.

[0149] In this embodiment, the inner wall surface 221 of the side wall is parallel to the outer circumferential surface 321 of the projecting section. In this way, when the inner wall surface 221 of the side wall and the outer circumferential surface 321 of the projecting section come into contact and press against each other, the force exerted between the inner wall surface of the side wall and the outer circumferential surface of the projecting section is distributed relatively uniformly, thereby reducing the stress concentration and the deformation of the housing 20 and the projecting section 32.

[0150] In some embodiments, the side wall 22 of the housing 20 is in press fit with the protruding section 32, so that the inner wall surface 221 of the side wall abuts the outer circumferential surface 321 of the protruding section.

[0151] The part of the preceding section 32 that projects into the housing 20 may be fully press-fitted with the housing 20 or partially press-fitted with the housing 20.

[0152] By way of an example where both the outer circumferential surface 321 of the protruding section and the inner wall surface 221 of the side wall are cylindrical surfaces, before the end cap 30 is placed on the housing 20, the diameter of the outer circumferential surface 321 of the protruding section is larger than the diameter of the inner wall surface 221 of the side wall. In this way, the part with which the protruding section 32 projects into the housing 20 is in a press fit with the housing 20 after the protruding section 32 is inserted into the housing 20.

[0153] In this embodiment, the press fit increases the connection strength between the housing 20 and the end cap 30 and improves the sealing performance. In this embodiment, the strength of the protruding section 32 is reduced by the recessed section 33, thus reducing the force exerted between the protruding section 32 and the housing 20 as the protruding section 32 extends into the housing 20. In this way, even with a press fit of the housing 20 with the protruding section 32, the formation of particles can be reduced, the risk of deformation of the housing 20 is decreased, and the safety performance of the battery cell 7 is improved.

[0154] In some embodiments, the inner wall surface 221 of the side wall is welded to the outer circumferential surface 321 of the projecting section to form a first weld section W1. In the thickness direction Z, which extends away from the electrode arrangement 10, the first weld section W1 does not project beyond the outer surface 312 of the cap body.

[0155] Optionally, the preceding section 32 and the side wall 22 can be joined by laser welding. When welding the preceding section 32 to the side wall 22, a laser beam is directed at the joint between the outer circumferential surface 321 of the preceding section and the inner wall surface 221 of the side wall. The laser beam melts and joins at least a portion of the outer circumferential surface 321 of the preceding section and a portion of the inner wall surface 221 of the side wall.

[0156] In this embodiment, the first weld section W1 closes the opening 21 to provide a seal and reduce the risk of electrolyte solution leaking from the gap between the outer circumferential surface 321 of the protruding section and the inner wall surface 221 of the side wall.

[0157] When welding the protruding section 32 to the housing 20, if the protruding section 32 is in a press fit with the housing 20, no external device for securing the end cap 30 is required, thus simplifying the assembly process. Furthermore, the outer circumferential surface 321 of the protruding section abuts the inner wall surface 221 of the side wall, thereby reducing the risk of the electrode assembly 10 being burned by the laser beam directed into the housing 20. The press fit can also block gaseous byproducts generated during welding, reducing the passage of gaseous byproducts between the outer circumferential surface 321 of the protruding section and the inner wall surface 221 of the side wall, and thus reducing the risk of the electrode assembly separator being burned.

[0158] In this embodiment, in the thickness direction Z, which extends away from the electrode arrangement 10, an exposed surface of the first weld section W1 does not extend beyond the outer surface 312 of the cap body.

[0159] The cap body 31 can serve as a supporting structure for the battery cell 7. After the battery cell 7 has been installed in an electrical device, an external support structure can support the battery cell 7 via the cap body 31. In this embodiment, the first weld section W1 does not project beyond the outer surface 312 of the cap body in the direction away from the electrode arrangement 10, thereby reducing the force between the external support structure and the first weld section W1, reducing the risk of breakage of the first weld section W1, and ensuring high joint strength and sealing performance between the housing 20 and the end cap 30.

[0160] In some embodiments, the side wall 22 comprises a first outer end face 223 around the opening 21, and the first outer end face 223 is connected to the inner wall surface 221 of the side wall. In the thickness direction Z, the projecting section 32 comprises a second outer end face 322 at an end facing away from the electrode assembly 10. The second outer end face 322 is connected to the outer circumferential surface 321 of the projecting section. The first outer end face 223 is flush with the second outer end face 322. The first outer end face 223 and the second outer end face 322 are closer to the electrode assembly 10 than the outer surface 312 of the cap body.

[0161] The first outer end face 223 connects the inner wall surface 221 of the side wall with the outer wall surface 222 of the side wall. One end, forming the second outer end face 322 and oriented away from the outer circumferential surface 321 of the projecting section, is connected to a side wall surface of the recessed section 33.

[0162] Optionally, both the first outer end face 223 and the second outer end face 322 are perpendicular to the inner wall surface 221 of the side wall and to the outer circumferential surface 321 of the preceding section.

[0163] The first weld section W1 formed by the welding process is uneven and rough and may protrude from the first outer end face 223 and the second outer end face 322. If the first outer end face 223 is flush with the outer surface 312 of the cap body, the first weld section W1 may act as a load-bearing part of the battery cell 7, thus creating a risk of the first weld section W1 breaking.

[0164] This embodiment causes the first outer end face 223 and the second outer end face 322 to be located closer to the electrode arrangement 10 than the outer surface 312 of the cap body. This prevents the first weld section W1 from extending beyond the outer surface 312 of the cap body in the direction away from the electrode arrangement 10, even if it projects beyond the first outer end face 223 and the second outer end face 322. This reduces the force exerted on the first weld section W1, decreases the risk of breakage of the first weld section W1, and ensures high joint strength and sealing performance between the housing 20 and the end cap 30.

[0165] In some embodiments, the foregoing section 32 further comprises a guide surface 323 directed towards the side wall 22. The guide surface 323 is connected to an end that forms the outer circumferential surface 321 of the foregoing section and is located near the electrode arrangement 10. The guide surface 323 is inclined away from the inner wall surface 221 of the side wall towards the outer circumferential surface 321 of the foregoing section in order to guide the foregoing section 32 so that it extends into the housing 20.

[0166] The guide surface 323 is positioned at a distance from the inner wall surface 221 of the side wall. In the direction from the end cap 30 to the electrode arrangement 10, the gap between the guide surface 323 and the inner wall surface 221 of the side wall gradually increases along the radial direction.

[0167] By providing a tilted guide surface 323 on the foreground section 32 in this embodiment, the foreground section 32 can be guided into the housing 20 during a process for fitting the end cap 30 to the housing 20 (in particular when the foreground section 32 is in press fit with the housing 20), thereby simplifying the assembly process and improving assembly efficiency.

[0168] Fig. Figure 7 is a schematic sectional view of a battery cell according to further embodiments of the present application.

[0169] In some embodiments, the housing 20 also includes a flanged section 24. The flanged section 24 is connected to the side wall 22 and bent towards the side wall 22 in the direction of the cap body 31 to cover the first welded section W1.

[0170] The flange section 24 and the side wall 22 are a single-piece structure and are formed by a flange operation.

[0171] An opening 21 is formed at one end, which is located at the flange section 24 and is oriented away from the side wall 22.

[0172] In a process for fitting the end cap 30 to the housing 20, the projecting section 32 of the end cap 30 is inserted into the housing 20, and then the projecting section 32 is welded to the side wall 22 to form a first weld section W1. After completion of the welding process, a portion of the housing 20 located near the opening 21 is calendered to form a flange section 24 that covers the first weld section W1.

[0173] In this embodiment, the flange section 24 can protect the first weld section W1, reduce the risk of corrosion and damage to the first weld section W1, and ensure high joint strength and sealing performance between the housing 20 and the end cap 30.

[0174] In some embodiments, a surface belonging to the flange section 24 and oriented away from the electrode arrangement 10 is flush with the outer surface of the cap body.

[0175] Fig. 8 is a schematic sectional view of a battery cell according to a further embodiment of the present application; Fig. 9 is a detailed view of a circled position B of the in Fig. 8 battery cell shown; and Fig. 10 is a detailed view of a rectangular position C, which is in Fig. 9 is shown.

[0176] As in Fig. 8 to Fig. As shown in Figure 10, in some embodiments the end cap 30 further comprises an extension section 36 that projects beyond the outer circumferential surface 321 of the projecting section and surrounds the projecting section 32. An inner surface 361 of the extension section is welded to a first outer end face 223 of the side wall 22 around the opening, so that the housing 20 and the end cap 30 are joined as one piece.

[0177] The extension section 36 comprises an inner surface and an outer surface arranged opposite each other along the thickness direction Z. The inner surface 361 of the extension section faces the electrode arrangement 10. Optionally, the extension section 36 is a ring-shaped flat plate structure. The inner surface 361 and the outer surface 362 of the extension section are both planar.

[0178] The extension section 36 and the side wall 22 are arranged along the thickness direction Z. The inner surface 361 of the extension section can be parallel to the first outer end face 223.

[0179] Optionally, when welding the extension section 36 to the side wall 22, the laser beam can be directed at a connection point between the first outer end face 223 and the inner surface 361 of the extension section. After completion of the welding process, at least a portion of the inner surface 361 of the extension section and at least a portion of the first outer end face 223 are melted and joined together.

[0180] The inner surface 361 of the extension section is welded to the first outer end face 223 of the side wall 22 to form a second welded section W2.

[0181] The first outer end face 223 is located at an outermost end of the housing 20. In this embodiment, the inner surface 361 of the extension section abuts the first outer end face 223.

[0182] In this embodiment, the first outer end face 223 serves, in a process for fitting the end cap 30 to the housing 20, to limit the position of the end cap 30 in the thickness direction Z, thereby reducing the risk of over-inserting the end cap 30 into the housing 20 and improving the efficiency of the assembly.

[0183] In some embodiments, the foreground section 32 is in clearance fit with the housing 20 to form a clearance between the outer circumferential surface 321 of the foreground section and the inner wall surface 221 of the side wall.

[0184] By way of an example where both the outer circumferential surface 321 of the protruding section and the inner wall surface 221 of the side wall are cylindrical surfaces, before the end cap 30 is placed on the housing 20, the diameter of the outer circumferential surface 321 of the protruding section is smaller than the diameter of the inner wall surface 221 of the side wall. In this way, after the protruding section 32 extends into the housing 20, the portion with which the protruding section 32 extends into the housing 20 is in clearance fitting with the housing 20.

[0185] In the above technical solution, the clearance fit not only ensures proper limitation of the position of the aforementioned section 32 by the housing 20, but also reduces the force exerted between the aforementioned section 32 and the housing 20 as the aforementioned section 32 extends into the housing 20, thereby reducing the risk of friction between the aforementioned section 32 and the housing 20, reducing the particles generated, reducing the deformation of the housing 20, and improving the safety performance of the battery cell 7.

[0186] In some embodiments, the gap between the outer circumferential surface 321 of the preceding section and the inner wall surface 221 of the side wall in a direction pointing from the electrode arrangement 10 to the side wall 22 is 0.02 mm to 0.5 mm.

[0187] For example, “the direction pointing from the electrode arrangement to the side wall” could be the radial direction.

[0188] For example, the gap between the outer circumferential surface 321 of the projecting section and the inner wall surface 221 of the side wall in the direction from the electrode arrangement 10 to the side wall 22 is L1. The smaller the value of L1, the higher the risk of friction between the outer circumferential surface 321 of the projecting section and the inner wall surface 221 of the side wall, and the higher the risk of particle generation. The larger the value of L1, the greater the area in which the projecting section 32 is movable after it extends into the housing 20, and the higher the risk of a poor weld between the extension section 36 and the housing 20. Based on tests, the inventor sets the value of L1 to between 0.02 mm and 0.5 mm to mitigate the risk and improve safety performance.

[0189] In some embodiments, a relief slot 363 is arranged on the inner surface 361 of the extension section. The relief slot 363 is arranged around the projecting section 32, and a slotted wall surface of the relief slot 363 is configured to connect the inner surface 361 of the extension section and the outer circumferential surface 321 of the projecting section.

[0190] The recessed section 33 and the projecting section 32 can be formed by a forming process. The inventor has found that during forming, a stress concentration occurs at the junction between the projecting section and the extension section. To reduce this stress concentration, the inventor attempts to incorporate a rounded corner at the junction between the projecting section and the extension section. However, after formation by forming, the rounded surface is created at the junction between the inner surface of the extension section and the outer circumferential surface. The rounded surface is relatively smooth and can abut the first outer end face while the projecting section is being inserted into the housing, thus preventing the first outer end face from a tight fit against the inner surface of the extension section.

[0191] For this reason, the inventor provides a relief slot 363 on the extension section 36. A portion of the extension section 36 opposite the relief slot 363 is connected to the projecting section 32. The relief slot 363 is recessed to provide a flow space for material from the projecting section during the formation of the projecting section 32. In this way, the rounded corner is formed on the portion of the extension section 36 that is opposite the relief slot 363. The rounded surface is part of the diaphragm wall surface of the relief slot 363. The diaphragm wall surface is recessed relative to the inner surface 361 of the extension section. Therefore, this embodiment ensures that the first outer end face 223 rests smoothly against the inner surface 361 of the extension section.

[0192] In some embodiments, an outer surface 362 of the extension section is flush with the outer surface 312 of the cap body.

[0193] In this embodiment, the external support structure can support the battery cell 7 via the extension section 36 and the cap body 31, thereby increasing the area of ​​the load-bearing part of the end cap 30 and increasing the stability of the battery cell 7.

[0194] In some embodiments, the extension section 36 does not extend beyond the outer wall surface 222 of the side wall in the direction that points from the electrode arrangement 10 to the side wall 22.

[0195] This embodiment prevents the extension section 36 from increasing the maximum size of the battery cell 7 and ensures a high energy density of the battery cell 7. Furthermore, the end cap 30 is relatively thin. The extension section 36 could scratch other external components if it protrudes beyond the outer wall surface 222 of the side wall.

[0196] In some embodiments, the outer wall surface 222 of the side wall extends from the electrode arrangement 10 to the side wall 22 by 0.02 mm to 0.5 mm beyond the extension section.

[0197] The second weld section W2, formed by welding the inner surface 361 of the extension section to the first outer end face 223 of the side wall 22, can project beyond an end face 364 of the extension section 36. If the outer wall surface 222 of the side wall is flush with the end face 364 of the extension section 36, which faces away from the projecting section 32, the second weld section W2 can project beyond the outer wall surface 222 of the side wall, thereby increasing the maximum size of the battery cell 7 and potentially scratching other external elements. Therefore, in this embodiment, the outer wall surface 222 of the side wall projects beyond the extension section 36 to reduce the risk of the second weld section W2 projecting beyond the outer wall surface 222 of the side wall.

[0198] Looking towards the side wall 22 from the electrode arrangement 10, the outer wall surface 222 of the side wall extends beyond the extension section 36 by an amount L2. The smaller the value of L2, the greater the risk that the second weld section W2 will project beyond the outer wall surface 222 of the side wall. The larger the value of L2, the smaller the contact area between the extension section 36 and the side wall 22, and the lower the bond strength between the extension section 36 and the side wall 22.

[0199] Based on tests, the inventor sets the value of L2 to 0.02 mm to 0.5 mm, thus minimizing, provided there is high connection strength, the risk that the second weld section W2 protrudes beyond the outer wall surface 222 of the side wall.

[0200] In some embodiments, in the direction pointing from the electrode arrangement 10 to the side wall 22, the amount L3 by which the extension section 36 extends beyond the outer circumferential surface 321 of the protruding section is less than the wall thickness of the side wall 22.

[0201] For example, L3 is a gap between the end face 364 of the extension section 36 and the outer circumferential surface 321 of the protruding section in a radial direction.

[0202] In this embodiment, when the outer circumferential surface 321 of the protruding section abuts the inner wall surface 221 of the side wall, since the wall thickness of the side wall 22 is greater than the amount by which the extension section 36 projects beyond the outer circumferential surface 321 of the protruding section, the outer wall surface 222 of the side wall extends beyond the extension section 36 in the direction of the side wall 22 from the electrode arrangement 10.

[0203] Fig. Figure 11 is a schematic flowchart of a process for manufacturing a battery cell.

[0204] As in Fig. As shown in 11, the process for manufacturing a battery cell comprises the following steps: S100: Providing a housing in which an opening is formed; S200: Providing an electrode assembly and installing the electrode assembly into the housing; S300: Providing an end cap, wherein the end cap comprises a cap body and a section projecting around the cap body, the projecting section being directed from an inner surface of the cap body, wherein a recessed section is formed on the end cap at a position corresponding to the projecting section and the recessed section is recessed from an outer surface of the cap body; S400: Extend at least part of the preceding section into the housing in order to fit into the housing; and S500: Connect the end cap to the housing so that the end cap fits onto the opening and covers it.

[0205] The protruding section extends from an inner surface of the cap body towards the electrode assembly, the recessed section is recessed from an outer surface of the cap body towards the electrode assembly, and the recessed section is configured to dissipate stress while the protruding section extends into the housing.

[0206] It should be noted that with regard to the associated structure of the battery cell produced using the above manufacturing process for a battery cell, reference is made to the descriptions of the battery cells in the above embodiments.

[0207] When assembling a battery cell based on the preceding method for manufacturing a battery cell, it is not necessary to perform the preceding steps in the specified order. That is, the steps can be performed in the order mentioned in the embodiments, or the steps can be performed in a different order than described in the embodiments, or several steps can be performed simultaneously. For example, step S100 and step S300 are not necessarily performed sequentially, but can be performed simultaneously.

[0208] Fig. Figure 12 is a schematic block diagram of a system for manufacturing a battery cell according to some embodiments of the present application.

[0209] As in Fig. As shown in 12, the system 90 comprises a battery cell for manufacturing according to an embodiment of the present application: a first provisioning device 91, which is configured to provide a housing, wherein an opening is formed on the housing; a second provisioning device 92 configured to provide an electrode assembly and to mount the electrode assembly in the housing; a third provisioning device 93 configured to provide an end cap, the end cap comprising a cap body and a projecting section around the cap body, the projecting section extending from an inner surface of the cap body, a recessed section being formed on the end cap at a position corresponding to the projecting section, and the recessed section being recessed from an outer surface of the cap body; a first mounting device 94 configured such that at least a portion of the protruding section projects into the housing in order to fit into the housing; and a second mounting device 95, configured to connect the end cap and the housing so that the end cap fits the opening and covers it, wherein

[0210] The protruding section extends from an inner surface of the cap body towards the electrode assembly, the recessed section is recessed from an outer surface of the cap body towards the electrode assembly, and the recessed section is configured to dissipate stress while the protruding section extends into the housing.

[0211] Regarding the associated structure of the battery cell produced using the above manufacturing process, reference is made to the descriptions of the battery cells in the above embodiments.

[0212] It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other, provided that no contradictions arise.

[0213] Finally, it should be noted that the foregoing embodiments serve only to describe the technical solutions of the present application and do not limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, a person with average technical knowledge understands that the technical solutions described in the foregoing embodiments may still be modified or that some technical features of the technical solutions may be replaced by equivalent substitute features. Such modifications and substitutions do not result in the core of the corresponding technical solutions differing from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

[1] A battery cell comprising: a housing with an opening attached; an electrode arrangement housed within the casing; and an end cap configured to fit and cover the opening, the end cap comprising a cap body and a section projecting around the cap body, the projecting section extending from an inner surface of the cap body towards the electrode arrangement, and at least a portion of the projecting section being arranged in the housing and configured to fit into the housing, wherein a recessed section is formed on the end cap at a position corresponding to the protruding section, and the recessed section extends from an outer surface of the cap body towards the electrode arrangement and is configured to dissipate stress while the protruding section extends into the housing. [2] Battery cell according to claim 1, wherein in a thickness direction of the end cap a bottom surface of the recessed section is closer to the electrode arrangement than the entire inner surface of the cap body. [3] Battery cell according to claim 1 or 2, wherein a side wall of the housing extends along a thickness direction of the end cap and is arranged around the electrode arrangement, and an inner wall surface of the side wall and an outer circumferential surface of the protruding section both extend parallel to the thickness direction and are arranged opposite each other. [4] Battery cell according to claim 3, wherein the side wall of the housing is in press fit with the protruding section, so that the inner wall surface of the side wall abuts the outer circumferential surface of the protruding section. [5] Battery cell according to claim 3 or 4, wherein the inner wall surface of the side wall is welded to the outer circumferential surface of the foreground section to form a first welded section; and In the thickness direction extending away from the electrode arrangement, the first weld section does not protrude beyond the outer surface of the cap body. [6] Battery cell according to claim 5, wherein the side wall has a first outer end face around the opening and the first outer end face is connected to the inner wall surface of the side wall; and In the thickness direction, the foregoing section has a second outer end face at an end facing away from the electrode assembly, wherein the second outer end face is connected to the outer circumferential surface of the foregoing section, the first outer end face is flush with the second outer end face, and the first outer end face and the second outer end face are closer to the electrode assembly than the outer surface of the cap body. [7] Battery cell according to claim 5, wherein the housing further comprises a flange section, the flange section being connected to the side wall and bent towards the side wall in the direction of the cap body to cover the first weld section. [8] Battery cell according to claim 3, wherein the end cap further comprises an extension section which projects beyond the outer circumferential surface of the protruding section and surrounds the protruding section, and an inner surface of the extension section is welded to a first outer end face of the side wall around the opening, so that the housing and the end cap are joined as one piece. [9] Battery cell according to claim 8, wherein the foreground section is in clearance fit with the housing to form a clearance between the outer circumferential surface of the foreground section and the inner wall surface of the side wall. [10] Battery cell according to claim 9, wherein in a direction pointing from the electrode arrangement to the side wall the clearance between the outer circumferential surface of the protruding section and the inner wall surface of the side wall is 0.02 mm to 0.5 mm. [11] Battery cell according to one of claims 8 to 10, wherein a relief slot is arranged on the inner surface of the extension section, the relief slot is arranged around the protruding section and a slotted wall surface of the relief slot is configured to connect the inner surface of the extension section and the outer circumferential surface of the protruding section. [12] Battery cell according to one of claims 8 to 11, wherein an outer surface of the extension section is flush with the outer surface of the cap body. [13] Battery cell according to one of claims 8 to 12, wherein in a direction pointing from the electrode arrangement to the side wall the extension section does not project beyond an outer wall surface of the side wall. [14] Battery cell according to claim 13, wherein the outer wall surface of the side wall extends from the electrode arrangement to the side wall by 0.02 mm to 0.5 mm beyond the extension section. [15] Battery cell according to claim 13 or 14, wherein in the direction pointing from the electrode arrangement to the side wall, the amount by which the extension section extends beyond the outer circumferential surface of the protruding section is less than the wall thickness of the side wall. [16] Battery cell according to any one of claims 3 to 15, wherein the foreground section further comprises a guide surface oriented towards the side wall, wherein the guide surface is connected to an end which is the outer circumferential surface of the foreground section and which is close to the electrode arrangement, and wherein the guide surface is inclined away from the inner wall surface of the side wall towards the outer circumferential surface of the foreground section in order to guide the foreground section so that it extends into the housing. [17] Battery cell according to claim 1, wherein the foreground section abuts a first tab of the electrode arrangement to support the first tab. [18] Battery cell according to claim 17, wherein the foreground section is welded to the first tab to electrically connect the first tab and the end cap. [19] Battery cell according to any one of claims 1 to 18, wherein a first tab of the electrode arrangement is electrically connected to the housing via the end cap. [20] Battery cell according to claim 19, wherein the housing has a side wall and a bottom wall, the side wall extends along a thickness direction of the end cap and is arranged around the electrode assembly, the bottom wall is connected to an end of the side wall and is located on a side of the electrode assembly that points away from the end cap, and an electrode exit opening is arranged on the bottom wall; wherein a second tab is arranged on the electrode assembly at an end facing the bottom wall, and the first tab and the second tab have opposite polarities; and The battery cell further comprises an electrode connection which is located in the electrode outlet opening, and the electrode connection is electrically connected to the second tab. [21] Battery cell according to claim 20, wherein the bottom wall and the side wall have a one-piece structure. [22] Battery cell according to one of claims 19 to 21, wherein the first tab is a negative tab and the housing support material is steel. [23] Battery cell according to any one of claims 1 to 22, wherein the battery cell is a cylindrical cell. [24] Battery comprising a plurality of battery cells according to any one of claims 1 to 23. [25] Electrical device comprising the battery according to claim 24, wherein the battery is configured to supply electrical energy. [26] System for manufacturing a battery cell, comprising: a first provisioning device configured to provide a housing, wherein an opening is formed on the housing; a second staging device configured to stag an electrode assembly and mount the electrode assembly in the housing; a third provisioning device configured to provide an end cap, the end cap comprising a cap body and a projecting section around the cap body, the projecting section extending from an inner surface of the cap body, a recessed section being formed on the end cap at a position corresponding to the projecting section, and the recessed section being recessed from an outer surface of the cap body; a first mounting device configured such that at least part of the preceding section projects into the housing in order to fit into the housing; and a second mounting device configured to connect the end cap and the housing so that the end cap fits the opening and covers it, wherein the protruding section extends from an inner surface of the cap body towards the electrode assembly, the recessed section is recessed from an outer surface of the cap body towards the electrode assembly, and the recessed section is configured to dissipate stress while the protruding section extends into the housing.

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