Battery cells, batteries, electrical equipment, and methods and equipment for manufacturing battery cells.

Abstract

To provide a battery cell, a battery, an electrical device, and a method for manufacturing a battery cell that can more easily connect an electrode assembly to a case.SOLUTION: A battery cell includes a case, an electrode assembly, an end cap, and a current collecting member. The case has an opening. The electrode assembly is accommodated in the case. The end cap is fitted over the opening and hermetically connected to the case. The current collecting member is accommodated in the case and located on the side of the electrode assembly facing the end cap, and is arranged to connect the case and the electrode assembly to electrically connect the electrode assembly to the case. In the battery cell having such a structure, the current collecting member realizes an electrical connection between the electrode assembly and the case, and in the process of assembling the battery cell, the current collecting member can be connected to the case inside the case, and after the current collecting member is connected to the electrode assembly and the case, the end cap is fitted over the opening of the case and hermetically connected to the case.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] Cross - reference to Related Applications This application claims priority to International Patent Application PCT / CN2021 / 104779, filed on July 6, 2021, with the invention title "Battery Cell, Battery, Electrical Equipment, and Method and Equipment for Manufacturing Battery Cells", and all the contents of this application are incorporated herein by reference.

[0002] This application relates to the technical field of batteries, specifically to battery cells, batteries, electrical equipment, and methods and equipment for manufacturing battery cells. [Background Art]

[0003] The batteries widely used in vehicles are generally lithium - ion batteries, which are a type of secondary battery having advantages such as being small, having a high energy density, a high output density, a large number of cycles, and a long storage time.

[0004] A battery cell generally includes a case for accommodating an electrode assembly and an electrolyte, and an electrode assembly generally including a positive electrode sheet and a negative electrode sheet. Electrical energy is generated by the movement of metal ions (e.g., lithium ions) between the positive electrode sheet and the negative electrode sheet.

[0005] In a general battery cell, in order to make the case function as the positive output electrode or the negative output electrode of the battery cell, it is necessary to electrically connect the electrode assembly to the case. Currently, the electrical connection between the electrode assembly and the case is not relatively easy. [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] Embodiments of this application provide a battery cell, a battery, electrical equipment, and methods and equipment for manufacturing battery cells that can make the electrical connection between the electrode assembly and the case easier. [Means for Solving the Problems]

[0007] According to a first aspect, an embodiment of the present application provides a battery cell comprising: a case having an opening; an electrode assembly housed within the case; an end cap fitted to cover the opening and sealed to the case; and a current collector housed within the case and located on the side of the electrode assembly facing the end cap, and arranged to connect the case and the electrode assembly so that the electrode assembly is electrically connected to the case.

[0008] In the above proposed technology, the current collector is located on the side of the electrode assembly facing the end cap, the electrode assembly and the case are electrically connected by the current collector, the end cap is fitted over the opening of the case and sealed to the case. With this structure, during the assembly process of the battery cell, the current collector can be connected to the case from inside the case, and after connecting the current collector to the electrode assembly and the case, the end cap is fitted over the opening of the case and sealed to the case, thereby further facilitating the electrical connection between the electrode assembly and the case.

[0009] In some embodiments, the current collector is welded to the case.

[0010] In the above proposed technology, the current collector is welded to the case, the method of connecting the current collector and the case is simple, the strength of the connection between the current collector and the case can be ensured, and a stable overcurrent can be achieved between the current collector and the case.

[0011] In some embodiments, the current collector and the case are welded together to form a welded portion located inside the case that secures the current collector and the case.

[0012] In the above proposed technology, the welded portion formed by welding the current collector to the case is located inside the case. This reduces the risk of damage to the outer layer structure of the case caused by the weld being located outside the case when welding the current collector to the case, thereby reducing the risk of corrosion of the case and improving the lifespan of the battery cell.

[0013] In some embodiments, a first position limiting portion is provided on the inner surface of the case to restrict the end cap from moving along the direction facing the electrode assembly, and the current collector is welded to the first position limiting portion.

[0014] In the above proposed technology, the first position limiting portion acts as a position limiting force with respect to the end cap, thereby restricting the end cap from moving along the direction facing the electrode assembly. The current collector is welded to the first position limiting portion that acts as a limiting force with respect to the end cap, effectively utilizing the first position limiting portion and being advantageous for welding and fixing the current collector.

[0015] In some embodiments, the current collector is located on the side of the first position limiting portion facing the electrode assembly and includes a body portion for connecting the electrode assembly, the first position limiting portion is used to restrict the body portion from detaching from the case in a direction away from the electrode assembly.

[0016] In the above proposed technology, the first position limiting portion acts as a limiting force on the main body, and the first position limiting portion can prevent the main body from detaching from the case in a direction away from the electrode assembly. The first position limiting portion can isolate the end cap from the main body, and the main body does not significantly affect the sealing between the end cap and the case, ensuring airtightness between the end cap and the case.

[0017] In some embodiments, the main body is welded to the first position limiting portion, abutting against the side of the first position limiting portion that faces the electrode assembly.

[0018] In the above proposed technology, the main body is welded to the first position limiting portion, abutting against the side of the first position limiting portion that faces the electrode assembly. This provides good rigidity after the entire current collector member is fixed to the first position limiting portion, and increases the overcurrent area between the case and the current collector member by increasing the contact area between the current collector member and the first position limiting portion.

[0019] In some embodiments, the current collector further includes an elastic portion connected to the main body and in contact with and welded to the first position limiting portion.

[0020] In the above proposed technology, the elastic portion of the current collector is in contact with and welded to the first position limiting portion, and the elastic portion is elastically deformable in response to changes in the distance between the main body and the first position limiting portion, thereby reducing the risk of poor electrical connection between the main body and the electrode assembly due to movement of the electrode assembly within the case caused by vibrations of the battery cell.

[0021] In some embodiments, the elastic portion is an elastic sheet that is folded and provided on the main body.

[0022] In the above proposed technology, the elastic part is an elastic sheet that is folded and provided on the main body, resulting in a simple structure and excellent deformation capability.

[0023] In some embodiments, the current collector further includes a first connecting portion connected to the main body, at least a portion of which extends to the inner circumference of the first position limiting portion and is welded to the first position limiting portion.

[0024] In the above proposed technology, at least a portion of the first connection portion of the current collector member extends to the inner circumference of the first position limiting portion, and the first connection portion is welded to the first position limiting portion, thereby reducing the difficulty of welding the current collector member and the first position limiting portion.

[0025] In some embodiments, the first connecting portion is a convex portion extending along a direction away from the electrode assembly from the main body portion, and the convex portion is used to form a positioning alignment with the inner circumferential surface of the first position limiting portion.

[0026] In the above technical solution, the first connecting portion is a convex portion that forms a positioning alignment with the inner circumferential surface of the first position limiting portion. The convex portion forms a positioning alignment with the inner circumferential surface of the first position limiting portion, reduces the risk of the current collecting member shaking during the welding process between the first connecting portion and the first position limiting portion, reduces the welding difficulty, and enhances the strength after welding the first connecting portion to the first position limiting portion. At the same time, by increasing the contact area between the case and the current collecting member, the overcurrent area between the case and the current collecting member is increased.

[0027] In some embodiments, the main body portion has an inner surface facing the electrode assembly and an outer surface facing away from the electrode assembly. The convex portion extends along a direction away from the electrode assembly from the outer surface, and the current collecting member further includes a concave portion recessed into the convex portion along a direction away from the electrode assembly from the inner surface.

[0028] In the above technical solution, the current collecting member is provided with a concave portion recessed into the convex portion along a direction away from the electrode assembly from the inner surface of the main body portion. On the one hand, the material of the current collecting member is reduced, and the manufacturing cost is cut. On the other hand, the deformation ability of the convex portion is enhanced so that the convex portion elastically abuts against the first position limiting portion, ensuring good contact between the convex portion and the first position limiting portion.

[0029] In some embodiments, both the convex portion and the concave portion are annular structures extending along the circumferential direction of the first position limiting portion.

[0030] In the above technical solution, both the convex portion and the concave portion are annular structures extending along the circumferential direction of the first position limiting portion, endowing the convex portion with better deformation ability.

[0031] In some embodiments, in the direction in which the first connection portion extends from the main body portion toward the electrode assembly, one end of the first connection portion toward the main body portion does not exceed the first position limiting portion.

[0032] In the above proposed technology, the end of the first connection that faces the main body does not exceed the first position limit, the first connection is less likely to interfere with the end cap, and airtightness between the end cap and the case is ensured.

[0033] In some embodiments, the first connection portion is welded to the inner circumferential surface of the first position limiting portion, the inner circumferential surface has a boundary position, the radial dimension of the inner circumferential surface gradually increases from the boundary position to both ends of the inner circumferential surface, and in the direction in which the first connection portion extends from the main body portion toward the electrode assembly, one end of the first connection portion toward the main body portion extends beyond the boundary position.

[0034] In the above proposed technology, one end of the first connecting portion that faces the main body extends beyond the boundary position, thereby forming a welding groove between the outer surface of the first connecting portion and the first position limiting portion. This facilitates welding and fixing of the first connecting portion and the first position limiting portion, and ensures strength after welding the first connecting portion to the first position limiting portion.

[0035] In some embodiments, the first connection portion includes an extending segment connected to the main body and extending from the main body in a direction away from the electrode assembly, with at least a portion extending to the inner circumference of the first position limiting portion, and a position limiting segment connected to the extending segment and abutting against the side of the first position limiting portion away from the electrode assembly and welded to the first position limiting portion.

[0036] In the above proposed technology, the position limiting segment is welded to the first position limiting portion on the side opposite to the electrode assembly of the first position limiting portion. The position limiting segment performs a limiting function, increasing the rigidity after the current collector member is welded to the first position limiting portion, and increasing the contact area between the current collector member and the first position limiting portion, thereby increasing the overcurrent area between the case and the current collector member.

[0037] In some embodiments, the first position limiting portion is an annular structure extending along the circumferential direction of the case.

[0038] In the above proposed technology, the first position limiting portion has an annular structure, making it easy to manufacture by molding, and the first position limiting portion provides a limiting effect on the end cap around its entire circumference, ensuring the position limiting capability of the first position limiting portion relative to the end cap.

[0039] In some embodiments, roller grooves are provided at positions on the outer surface of the case corresponding to the first position limiting portion.

[0040] In the above proposed technology, roller grooves are provided on the outer surface of the case, and in the process of forming the roller grooves, the case forms a first position limiting portion at a position corresponding to the roller grooves, thereby simplifying the molding process of the first position limiting portion.

[0041] In some embodiments, the battery cell further comprises a sealing member, and the end cap and the case are sealed and connected by the sealing member.

[0042] In the above proposed technology, in order to ensure airtightness between the end cap and the case, the end cap and the case are sealed together by a sealing member.

[0043] In some embodiments, the sealing member is positioned to insulate and isolate the case from the end cap.

[0044] In the above proposed technology, the case and the end cap are insulated and isolated by a sealing member. The sealing member performs both a sealing and insulating function between the case and the end cap, ensuring airtightness between the end cap and the case while simultaneously reducing the risk of static electricity buildup on the end cap.

[0045] In some embodiments, the sealing member is positioned to cover the end cap along the circumferential direction of the opening.

[0046] In the above proposed technology, the sealing member covers the end cap along the circumferential direction of the opening of the case. On the one hand, this enhances the airtightness of the sealing member to the end cap and the case, and on the other hand, it improves the integration of the sealing member and the case. During the process of assembling the battery cell, the sealing member may be covered to the end cap, and then the end cap and sealing member may be attached to the case as a single unit.

[0047] In some embodiments, the case is provided with a second position limiting portion at one end of the opening to restrict the end cap from detaching from the case in a direction away from the electrode assembly, and at least a portion of the sealing member is positioned between the end cap and the second position limiting portion in the thickness direction of the end cap to achieve a sealed connection between the end cap and the case.

[0048] In the above proposed technology, the second position limiting portion acts as a limiting force on the end cap, preventing the end cap from detaching from the case in a direction away from the electrode assembly. At least a portion of the sealing member is located between the end cap and the second position limiting portion, achieving a sealed connection between the end cap and the case and ensuring good airtightness between the end cap and the case.

[0049] In some embodiments, the sealing member includes an enclosure and a second connecting portion connected to the enclosure, wherein at least a portion of the end cap is located within the enclosure, and the second connecting portion is located between the end cap and a second position limiting portion in the thickness direction of the end cap to achieve a sealed connection between the end cap and the case.

[0050] In the above proposed technology, the sealing member includes an enclosure and a second connecting portion that are interconnected, with at least a portion of the end cap located within the enclosure and the second connecting portion located between the end cap and the second position limiting portion. This provides a simple structure for the sealing member, ensures good airtightness between the end cap and the case, and provides good integration between the sealing member and the end cap.

[0051] According to the second aspect, an embodiment of the present application provides a battery comprising a plurality of battery cells according to any one embodiment of the first aspect.

[0052] According to a third aspect, an embodiment of the present application provides an electrical device comprising a battery cell according to any one embodiment of the first aspect.

[0053] According to a fourth aspect, an embodiment of the present application provides a method for manufacturing a battery cell, comprising: providing a case having an opening; providing an electrode assembly; providing an end cap; providing a current collector member; connecting the current collector member to the electrode assembly; housing the electrode assembly and the current collector member in the case; fitting the end cap over the opening and sealing the end cap and the case so that the current collector member is positioned on the side of the electrode assembly facing the end cap, wherein the case and the electrode assembly are electrically connected by the current collector member.

[0054] In some embodiments, the manufacturing method further includes welding the current collector to the case from the inside of the case before fitting the end cap over the opening.

[0055] According to a fifth aspect, an embodiment of the present application provides a battery cell manufacturing apparatus comprising: a first supplying apparatus for providing a case having an opening; a second supplying apparatus for providing an electrode assembly; a third supplying apparatus for providing an end cap; a fourth supplying apparatus for providing a current collector member; and an assembly apparatus used for connecting the current collector member to the electrode assembly, further housing the electrode assembly and the current collector member in the case, further fitting the end cap over the opening, and sealing the end cap and the case so that the current collector member is positioned on the side of the electrode assembly facing the end cap, wherein the case and the electrode assembly provide a battery cell manufacturing apparatus in which the case and the electrode assembly are electrically connected by the current collector member. [Brief explanation of the drawing]

[0056] To more clearly explain the technical concept of the embodiments of this application, the following is a brief description of the drawings to be used in the embodiments of this application. The following drawings show only some embodiments of this application and should not be considered limiting, and it should be understood that those skilled in the art can obtain other relevant drawings based on these drawings without any creative effort.

[0057] [Figure 1] This is a schematic diagram of the structure of a vehicle according to some embodiments of the present invention. [Figure 2] This is a schematic diagram of the structure of a battery according to some embodiments of the present invention. [Figure 3] This is an exploded view of a battery cell according to some embodiments of the present invention. [Figure 4] Figure 3 is a cross-sectional view of a battery cell. [Figure 5] This is a partial view of a battery cell according to some embodiments of the present invention. [Figure 6] A partial diagram of a battery cell relating to another embodiment of the present invention. [Figure 7] Figure 4 is a partial view of the battery cell shown. [Figure 8] This is a partial diagram of a battery cell relating to further embodiments of the present invention. [Figure 9] This is a flowchart of a method for manufacturing a battery cell according to some embodiments of the present invention. [Figure 10] This is a schematic diagram of the structure of a battery cell manufacturing facility according to some embodiments of the present invention. [Modes for carrying out the invention]

[0058] To further clarify the purpose, technical proposal, and advantages of this application, the technical proposal relating to the embodiments of this application will be described in detail below with reference to the drawings of the embodiments of this application. Clearly, the embodiments described herein are not all embodiments of this application, but only a selection. All other embodiments that can be obtained by a person skilled in the art without creative effort based on the embodiments of this application are all within the scope of this application.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art. Terms used herein are solely for the purpose of describing specific embodiments and are not intended to limit the application. The terms “including” and “having,” and any variations thereof, in the brief description of the specification, claims, and drawings of this application are intended to cover non-exclusive inclusion. Terms such as “first,” “second,” etc., in the specification, claims, or drawings are used to distinguish different subjects, not to indicate a specific order or hierarchical relationship.

[0060] In this application, “Examples” means that a combination of specific features, structures, or properties described in the Examples may be included in at least one Example of this Application. The term “Examples” as it appears in this Specification does not necessarily refer to the same Example, nor does it mean that each Example is mutually exclusive, independent, or alternative to the others.

[0061] In the description of this application, unless otherwise specified or limited, technical terms such as "attachment," "connection," "connection," and "mounting" should be understood in a broad sense. For example, this could refer to a fixed connection, a removable connection, or integration; it could refer to a direct connection, an indirect connection via an intermediate medium, or internal communication between two elements. A person skilled in the art will be able to understand the specific meaning of these terms in this application depending on the specific situation.

[0062] In the embodiments of this application, the same reference numerals indicate the same parts, and for the sake of simplification, detailed descriptions of the same parts are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various members in the embodiments of this application shown in the drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are illustrative and do not limit the present application in any way.

[0063] The term "multiple" as used in this application means two or more (including two).

[0064] In this application, the battery cell may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, and there are no limitations to these in the embodiments of this application. The battery cell may be cylindrical, flat, rectangular, or have other shapes, and there are no limitations to these in the embodiments of this application. Battery cells are generally classified into three types based on their packaging: cylindrical cells, prismatic cells, and pouch-type cells, but there are no limitations to these in the embodiments of this application.

[0065] The battery referred to in the embodiments of this application is a single physical module containing one or more battery cells to provide higher voltage and capacity. For example, the battery as referred to in this application may include a battery module or a battery pack. The battery typically includes a housing for packaging one or more battery cells. The housing can prevent the charging and discharging of the battery cells from being affected by liquids or other foreign matter.

[0066] A battery cell comprises an electrode assembly consisting of a positive electrode sheet, a negative electrode sheet, and a separator, and an electrolyte. The battery cell operates primarily by the movement of metal ions between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer being coated on the surface of the positive electrode current collector, and positive electrode current collectors without the positive electrode active material layer protruding from positive electrode current collectors with the positive electrode active material layer, which are referred to as positive electrode tabs. Taking a lithium-ion battery as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. Negative electrode current collectors without the negative electrode active material layer protrude from the negative electrode current collectors with the negative electrode active material layer, and these negative electrode current collectors without the negative electrode active material layer are negative electrode tabs. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon, silicon, or the like. Multiple positive electrode tabs are stacked together to allow large currents to pass without melting, and multiple negative electrode tabs are stacked together. The separator material may be PP (polypropylene) or PE (polyethylene), etc. Furthermore, the electrode assembly may be a wound type structure or a laminated type structure, and the embodiments of this application are not limited to these.

[0067] In typical battery cells, the electrode assembly needs to be electrically connected to the case in order for the case to function as the positive or negative output electrode of the battery cell, and currently, electrical connection between the electrode assembly and the case is not relatively easy.

[0068] The inventors found that in a battery cell, the case has a hollow structure with an opening at the top, and the electrode assembly is electrically connected to the case. Generally, the electrical connection between the electrode assembly and the case is achieved by welding the bottom wall of the case to the electrode assembly from the outside of the case. However, because the electrode assembly is located inside the case, it is not easy to judge the degree of welding between the electrode assembly and the bottom wall of the case, making it difficult to achieve an electrical connection between the electrode assembly and the case.

[0069] In view of this, the embodiment of the present application provides a battery cell in which the electrode assembly and the case are electrically connected via the current collector, the current collector is provided on the side of the electrode assembly facing the end cap, the end cap is fitted over the opening of the case, and the end cap is sealed and connected to the case.

[0070] In such a battery cell, the current collector is used to establish an electrical connection between the electrode assembly and the case. When assembling the battery cell, the current collector can be connected to the case from inside the case. After connecting the current collector to the electrode assembly and the case, the end cap is fitted over the opening in the case to create a sealed connection, further facilitating the electrical connection between the electrode assembly and the case.

[0071] The battery cell described in the embodiment of this application is applicable to batteries and electrical equipment using batteries.

[0072] Electrical equipment may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and power tools. Vehicles may be gasoline-powered cars, natural gas cars, or new energy vehicles. New energy vehicles may include pure electric vehicles, hybrid cars, or range-extender electric vehicles. Spacecraft include airplanes, rockets, space shuttles, and spacecraft. Electric toys include stationary or mobile electric toys such as game consoles, electric car toys, electric boat toys, and electric airplane toys. Power tools include power tools for metal cutting, grinding, assembly, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric chips. The embodiments of this application are not particularly limited to the aforementioned electrical equipment.

[0073] In the following embodiments, for the sake of explanation, a vehicle will be used as an example to describe the electrical equipment.

[0074] Referring to Figure 1, Figure 1 is a schematic diagram of the structure of a vehicle 1000 according to a partial embodiment of the present invention. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be located at the bottom, top, or rear of the vehicle 1000. The battery 100 is used to power the vehicle 1000, and for example, the battery 100 can be used as the operating power source for the vehicle 1000.

[0075] The vehicle 1000 may include a controller 200 and a motor 300. The controller 200 is used to supply power from the battery 100 to the motor 300, for example, to control the power used for operation when the vehicle 1000 is started, during navigation, and while driving.

[0076] In some embodiments of the present invention, the battery 100 not only functions as an operating power source for the vehicle 1000, but also as a power source for driving the vehicle 1000, and can provide driving force to the vehicle 1000 as a substitute or partial substitute for gasoline or natural gas.

[0077] In some embodiments, referring to Figure 2, Figure 2 is a schematic diagram of the structure of a battery 100 according to some embodiments of the present invention, and the battery 100 comprises a plurality of battery cells 10. The plurality of battery cells 10 may be connected in series, in parallel, or in series-parallel. Series-parallel connection means that there are series connections and parallel connections among the plurality of battery cells 10.

[0078] In some embodiments, the battery 100 may further include a busbar member, which allows for the electrical connection of multiple battery cells 10 via the busbar member in order to realize a series connection, parallel connection, or series-parallel connection of multiple battery cells 10.

[0079] The busbar members may be metal conductors such as copper, iron, aluminum, steel, or aluminum alloys.

[0080] In some embodiments, the battery cell 10 may further include a housing 20 for housing the battery cell 10. The housing 20 may include a first portion 21 and a second portion 22, with the first portion 21 and the second portion 22 fitting together to cover each other and form a housing chamber for housing the battery cell 10. Of course, the connection between the first portion 21 and the second portion 22 may be sealed by a sealing element, which may be a sealing ring, sealant, or the like.

[0081] Here, the first part 21 and the second part 22 may be of various shapes, such as a rectangular parallelepiped or a cylindrical shape. The first part 21 may be a hollow structure with one side open, and the second part 22 may also be a hollow structure with one side open. When the open side of the second part 22 is fitted over the open side of the first part 21, a housing 20 with a housing chamber is formed. Of course, it is also possible for the first part 21 to be a hollow structure with one side open, and the second part 22 to be a plate-like structure, and for the second part 22 to be fitted over the open side of the first part 21 to form a housing 20 with a housing chamber.

[0082] Referring to Figure 3, Figure 3 is an exploded view of a battery cell 10 according to a partial embodiment of the present application. The battery cell 10 may include a case 11, an electrode assembly 12, an end cap 13, a current collector 14, and a sealing member 15.

[0083] The case 11 is a component for housing the electrode assembly 12, and may be a hollow structure with one end open or a hollow structure with both ends open. The material of the case 11 may be various types, such as copper, iron, aluminum, steel, or aluminum alloy. The case 11 may have various shapes, such as a cylinder or a rectangular parallelepiped. Exemplarily, in Figure 3, the case 11 is a cylinder, and the battery cell 10 shown in Figure 3 is a cylindrical battery 100.

[0084] The electrode assembly 12 is a component in which an electrochemical reaction takes place within the battery cell 10. The electrode assembly 12 may include a main body and tabs, the tabs extending from the main body so as to protrude from the ends of the main body. The main body may include a positive electrode sheet, a negative electrode sheet, and a separator. The main body may be a wound structure formed by winding the positive electrode sheet, separator, and negative electrode sheet. The main body may also be a laminated structure formed by stacking the positive electrode sheet, separator, and negative electrode sheet.

[0085] The positive electrode sheet includes a positive electrode fluid collector and a positive electrode active material layer coated on both opposing sides of the positive electrode current collector. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer coated on both opposing sides of the negative electrode current collector. The main body is the portion of the electrode assembly 12 corresponding to the area of ​​the sheet coated with the active material layer, and the tabs are portions of the sheet not coated with the active material layer. The tabs may be divided into positive electrode tabs and negative electrode tabs, each protruding from both ends of the main body.

[0086] The end cap 13 is a component that covers and fits over the opening of the case 11, isolating the internal environment of the battery cell 10 from the external environment. The end cap 13 covers and fits over the opening of the case 11, and together the end cap 13 and the case 11 define a sealed space for housing the electrode assembly 12, electrolyte, and current collector 14. The shape of the end cap 13 can be matched to the shape of the case 11. For example, if the case 11 has a rectangular parallelepiped structure, the end cap 13 has a rectangular plate-like structure that fits the case 11, and furthermore, if the case 11 has a cylindrical structure, the end cap 13 has a disc-like structure that fits the case 11. The material of the end cap 13 can also be of various types, and the end cap 13 may be made of metal such as copper, iron, aluminum, steel, or aluminum alloy, and the material of the end cap 13 may be the same as or different from the material of the case 11.

[0087] In the battery cell 10, there may be one or two end caps 13. In the case of a hollow case 11 with one end open, one end cap 13 is provided accordingly. In the case of a hollow case 11 with both ends open, two end caps 13 are provided accordingly, and the two end caps 13 are fitted to cover the two openings of the case 11, respectively. One of the positive and negative electrode tabs of the electrode assembly 12 is electrically connected to one end cap 13, and the other is electrically connected to the case 11. In the embodiment of the case 11 with a hollow case open at one end, an electrode terminal 16 (not shown in Figure 3) may be provided at the end of the case 11 opposite the end cap 13. The electrode terminal 16 and the case 11 are insulated from each other, and one of the positive and negative electrode tabs of the electrode assembly 12 is electrically connected to the case 11, and the other is electrically connected to the electrode terminal 16.

[0088] The current collector 14 is a component that connects the case 11 and the electrode assembly 12, thereby realizing an electrical connection between the electrode assembly 12 and the case 11, so that the case 11 functions as one of the output electrodes of the battery cell 10. In embodiments in which the electrode assembly 12 is electrically connected to the electrode terminal 16, the positive or negative electrode tab of the electrode assembly 12 may be electrically connected to the electrode terminal 16 via one current collector 14. For example, the negative electrode tab of the electrode assembly 12 may be electrically connected to the case 11 via one current collector 14, and the positive electrode tab of the electrode assembly 12 may be electrically connected to the electrode terminal 16 via another current collector 14.

[0089] The current collector 14 may be a metal conductor such as copper, iron, aluminum, steel, or an aluminum alloy.

[0090] The sealing member 15 is provided between the end cap 13 and the case 11 and is a component that realizes a sealed connection between the end cap 13 and the case 11. The sealing member 15 may be made of various materials, such as rubber or plastic.

[0091] Referring to Figure 4, which is a cross-sectional view of the battery cell 10 shown in Figure 3. Embodiments of the present application provide a battery cell 10 comprising a case 11, an electrode assembly 12, an end cap 13, and a current collector 14. The case 11 has an opening. The electrode assembly 12 is housed within the case 11. The end cap 13 is fitted over the opening and is sealed to the case 11. The current collector 14 is housed within the case 11 and is located on the side of the electrode assembly 12 facing the end cap 13. The current collector 14 is positioned to connect the case 11 and the electrode assembly 12 so that the electrode assembly 12 is electrically connected to the case 11.

[0092] The current collector 14 is a component that realizes the electrical connection between the electrode assembly 12 and the case 11. The current collector 14 is connected to the case 11 while being connected to the electrode assembly 12. The current collector 14 is connected to the electrode assembly 12, and may be connected to the positive electrode tab of the electrode assembly 12 or to the negative electrode tab of the electrode assembly 12. The connection between the current collector 14 and the electrode assembly 12 may be fixed by welding the current collector 14 to the positive electrode tab or negative electrode tab of the electrode assembly 12, or it may be simply a matter of the current collector 14 contacting the positive electrode tab or negative electrode tab of the electrode assembly 12. The connection between the current collector 14 and the case 11 may be fixed by welding the current collector 14 to the case 11, or it may be simply a matter of the current collector 14 contacting the case 11.

[0093] In the embodiment of the present invention, the current collector 14 is located on the side of the electrode assembly 12 facing the end cap 13, the electrode assembly 12 and the case 11 are electrically connected via the current collector 14, the end cap 13 is fitted over the opening of the case 11 and the end cap 13 is sealed to the case 11. In a battery cell 10 with such a structure, the current collector 14 enables the electrical connection between the electrode assembly 12 and the case 11, the current collector 14 can be connected to the case 11 from inside the case 11, and after connecting the current collector 14 to the electrode assembly 12 and the case 11, the end cap 13 is fitted over the opening of the case 11 and sealed to the case 11, thereby further facilitating the electrical connection between the electrode assembly 12 and the case 11.

[0094] In a typical battery cell 10, the bottom wall of the case 11 is welded to the tab, and during the welding process between the bottom wall of the case 11 and the tab, the bottom wall of the case 11 is prone to damage, leading to leakage and affecting the performance of the battery cell 10. On the other hand, in the embodiment of the present invention, the electrode assembly 12 and the case 11 are electrically connected by a current collector 14, and the end cap 13 is sealed and connected to the case 11, and the electrode assembly 12 is not directly connected to the end cap 13, so the battery cell 10 is less likely to leak from the end cap 13 side.

[0095] For example, the current collector 14 connects the case 11 to the negative electrode tab of the electrode assembly 12 so that the case 11 functions as the negative output terminal of the battery cell 10. The electrode terminal 16 at one end away from the end cap 13 of the case 11 is electrically connected to the positive electrode tab of the electrode assembly 12 so that the electrode terminal 16 functions as the positive output terminal of the battery cell 10.

[0096] In some embodiments, the current collector 14 is welded to the case 11. The method of connecting the current collector 14 to the case 11 is simple, ensuring a strong connection between the current collector 14 and the case 11, and enabling stable overcurrent between the current collector 14 and the case 11.

[0097] When welding the current collector 14 to the case 11, the welding may be performed outside the case 11, for example, by a through-welding method, or the current collector 14 may be welded to the case 11 from the outside. When welding is performed outside the case 11, the welded portion 17 formed by welding the current collector 14 to the case 11 is located outside the case 11. However, when welding is performed inside the case 11, the welded portion 17 formed by welding the current collector 14 to the case 11 is located inside the case 11.

[0098] In some embodiments, the current collector 14 and the case 11 are welded together to form a welded portion 17 located inside the case 11 for fixing the current collector 14 and the case 11.

[0099] The welded joint 17 serves to fix the current collector 14 and the case 11; that is, the current collector 14 is fixed to the case 11 via the welded joint 17. The welded joint 17 may be solder connecting the current collector 14 and the case 11, or it may be a fused joint formed by the current collector 14 and the case 11 being fused together.

[0100] For example, if the case 11 is made of steel, and the welded joint 17 formed by welding the current collector 14 to the case 11 is located outside the case 11, the external protective layer of the case 11 is easily damaged during the welding process of the current collector 14 to the case 11, making it prone to corrosion.

[0101] On the other hand, in this embodiment, since the welded portion 17 formed by welding the current collector 14 to the case 11 is located inside the case 11, the risk of damage to the outer layer structure of the case 11 due to the welded portion 17 being located outside the case 11 when welding the current collector 14 to the case 11 is reduced, the risk of corrosion of the case 11 is reduced, and the service life of the battery cell 10 is improved.

[0102] In some embodiments, referring again to Figure 4, a first position limiting portion 112 is provided on the inner surface 111 of the case 11, which is used to restrict the end cap 13 from moving along the direction facing the electrode assembly 12. The current collector member 14 is welded to the first position limiting portion 112.

[0103] The inner surface 111 of case 11 refers to the inner surface of the side wall of case 11 that extends along the thickness direction Z of the end cap 13. The first position limiting portion 112 is a protrusion on the inner surface 111 of case 11 and is a structure for limiting the movement of the end cap 13 along the direction facing the electrode assembly 12. The first position limiting portion 112 and case 11 may be integrally molded or they may be molded separately and then joined together.

[0104] In this embodiment, the first position limiting portion 112 acts as a limiting force on the end cap 13, and the first position limiting portion 112 can restrict the end cap 13 from moving along the direction facing the electrode assembly 12. The current collector member 14 is welded to the first position limiting portion 112 that acts as a limiting force on the end cap 13, and the first position limiting portion 112 is effectively utilized, which is advantageous for welding and fixing the current collector member 14.

[0105] In some embodiments, referring to Figure 5, which is a partial view of a battery cell 10 according to some embodiments of the present application, the current collector 14 includes a body portion 141 for connection to the electrode assembly 12, the body portion 141 being located on the side of the first position limiting portion 112 facing the electrode assembly 12, the first position limiting portion 112 being used to limit the body portion 141 from detaching from the case 11 in a direction away from the electrode assembly 12.

[0106] The main body portion 141 is the connection portion between the current collector member 14 and the electrode assembly 12. For example, the main body portion 141 is welded to the negative electrode tab of the electrode assembly 12. The entire current collector member 14 may be the main body portion 141, or only a part of the current collector member 14 may be the main body portion 141. Exemplarily, in Figure 5, the entire current collector member 14 is the main body portion 141.

[0107] The first position limiting portion 112 provides a limiting effect on the main body portion 141, and the first position limiting portion 112 can prevent the main body portion 141 from detaching from the case 11 in a direction away from the electrode assembly 12, and the first position limiting portion 112 can isolate the end cap 13 and the main body portion 141, and the main body portion 141 does not affect the sealing between the end cap 13 and the case 11, and airtightness between the end cap 13 and the case 11 is ensured.

[0108] In some embodiments, referring again to Figure 5, the main body 141 is welded to the first position limiting portion 112, abutting against the side of the first position limiting portion 112 facing the electrode assembly 12.

[0109] The main body portion 141 abuts against the side of the first position limiting portion 112 facing the electrode assembly 12, and as can be understood, the main body portion 141 abuts against the end face of the first position limiting portion 112 facing the electrode assembly 12, and the first position limiting portion 112 serves to prevent the main body portion 141 from moving in a direction away from the electrode assembly 12.

[0110] In this embodiment, the main body 141 abuts against the side of the first position limiting portion 112 facing the electrode assembly 12 and is welded to the first position limiting portion 112. This provides good rigidity after the entire current collector member 14 is fixed to the first position limiting portion 112, and increases the overcurrent area between the case 11 and the current collector member 14 by increasing the contact area between the current collector member 14 and the first position limiting portion 112.

[0111] For example, in Figure 5, the main body portion 141 has an outer surface 1412 facing away from the electrode assembly 12 in the thickness direction Z of the end cap 13, the first position limiting portion 112 has an inner circumferential surface 1121, and the welded portion 17 formed by welding the main body portion 141 to the first position limiting portion 112 is connected to the outer surface 1412 of the main body portion 141 and the inner circumferential surface 1121 of the first position limiting portion 112.

[0112] In some embodiments, referring to Figure 6, which is a partial view of a battery cell 10 according to another embodiment of the present invention. The current collector 14 may include an elastic portion 142, which is connected to the main body portion 141 and abuts against and is welded to the first position limiting portion 112.

[0113] The elastic portion 142 is an elastically deformable part of the current collector member 14 connected to the main body portion 141. In the thickness direction Z of the end cap 13, the elastic portion 142 is located on the side of the main body portion 141 facing the first position limiting portion 112. The elastic portion 142 and the main body portion 141 may be integrally molded or joined after being molded separately. The current collector member 14 may have one or more elastic portions 142. If the current collector member 14 has multiple elastic portions 142, the multiple elastic portions 142 may be distributed at intervals along the circumferential direction of the main body portion 141.

[0114] In this embodiment, the elastic portion 142 of the current collector 14 is in contact with the first position limiting portion 112 and welded to the first position limiting portion 112. The elastic portion 142 is elastically deformable in response to changes in the distance between the main body portion 141 and the first position limiting portion 112, thereby reducing the risk of poor electrical connection between the main body portion 141 and the electrode assembly 12 due to movement of the electrode assembly 12 within the case 11 caused by vibrations of the battery cell 10.

[0115] In some embodiments, referring again to Figure 6, the elastic portion 142 is an elastic sheet that is folded and provided on the main body portion 141, and such an elastic portion 142 has a simple structure, excellent deformability, and ensures that the elastic portion 142 has a relatively large contact area with the first position limiting portion 112.

[0116] In other embodiments, the elastic portion 142 may have a different structure, for example, a spring structure in which the elastic portion 142 is connected to the main body portion 141.

[0117] In some embodiments, referring to Figure 7, which is a partial view of the battery cell 10 shown in Figure 4, the current collector 14 may further include a first connection portion 143 which is connected to the main body portion 141, and at least a portion of the first connection portion 143 extends to the inner circumference of the first position limiting portion 112, and the first connection portion 143 is welded to the first position limiting portion 112.

[0118] The first connection portion 143 is the portion to which the current collector member 14 is welded to the first position limiting portion 112, and at least a part of this portion extends to the inner circumference side of the first position limiting portion 112. Taking the case of the first position limiting portion 112 having an inner circumferential surface 1121 as an example, at least a part of the first connection portion 143 extends to the inner circumference side of the first position limiting portion 112, that is, at least a part of the first connection portion 143 extends into the space defined by the inner circumferential surface 1121 of the first position limiting portion 112.

[0119] In this embodiment, the first connecting portion 143 is welded to the first position limiting portion 112, and a part of the first connecting portion 143 of the current collector member 14 extends to the inner circumference of the first position limiting portion 112. Therefore, the first connecting portion 143 may be directly welded to the first position limiting portion 112, thereby reducing the difficulty of welding the current collector member 14 and the first position limiting portion 112.

[0120] Furthermore, if the first connection portion 143 of the current collector member 14 is welded to the first position limiting portion 112, the main body portion 141 of the current collector member 14 may abut against the side of the first position limiting portion 112 facing the electrode assembly 12, or the main body portion 141 may be provided with a gap between it and the first position limiting portion 112 in the thickness direction Z of the end cap 13. In Figure 7, in order to increase the overcurrent area between the current collector member 14 and the case 11, the main body portion 141 abuts against the side of the first position limiting portion 112 facing the electrode assembly 12.

[0121] In some embodiments, referring again to Figure 7, the first connecting portion 143 is a protrusion extending from the main body portion 141 in a direction away from the electrode assembly 12, and the protrusion is used to form a positional alignment with the inner circumferential surface 1121 of the first position limiting portion 112.

[0122] The protrusion forms a positional alignment with the inner circumferential surface 1121 of the first position limiting portion 112, and the outer circumferential surface of the protrusion contacts the inner circumferential surface 1121 of the first position limiting portion 112, thereby preventing the protrusion from swaying along a direction perpendicular to the thickness direction Z of the end cap 13.

[0123] In this embodiment, the first connecting portion 143 is a protrusion that forms a positional alignment with the inner circumferential surface 1121 of the first position limiting portion 112. Because the protrusion forms a positional alignment with the inner circumferential surface 1121 of the first position limiting portion 112, the risk of vibration of the current collector member 14 during the welding process between the first connecting portion 143 and the first position limiting portion 112 is reduced, the difficulty of welding is lowered, and the strength after welding the first connecting portion 143 to the first position limiting portion 112 is increased. At the same time, the contact area between the case 11 and the current collector member 14 is increased, thereby increasing the overcurrent area between the case 11 and the current collector member 14.

[0124] In some embodiments, referring again to Figure 7, the main body 141 has an inner surface 1411 facing the electrode assembly 12 and an outer surface 1412 facing away from the electrode assembly 12, and the protrusion extends from the outer surface 1412 of the main body 141 in a direction away from the electrode assembly 12. The current collector member 14 further includes a recess 144 that is recessed into the protrusion from the inner surface 1411 of the main body 141 in a direction away from the electrode assembly 12.

[0125] Providing the recess 144 in the current collector member 14 reduces the amount of material used in the current collector member 14, thereby lowering manufacturing costs. On the other hand, it increases the deformation capacity of the protrusion so that the protrusion elastically contacts the first position limiting portion 112, thereby ensuring good contact between the protrusion and the first position limiting portion 112.

[0126] In some embodiments, both the convex portion and the concave portion 144 are annular structures that extend along the circumferential direction of the first position limiting portion 112.

[0127] Since both the convex portion and the concave portion 144 have an annular structure, the convex portion has better deformability. When the convex portion receives a radial force from the first position limiting portion 112, the convex portion can contract and deform toward its central position, thereby bringing the convex portion and the first position limiting portion 112 into relatively close contact and ensuring good contact between the convex portion and the first position limiting portion 112.

[0128] In some embodiments, continuing to refer to Figure 7, in the direction in which the first connection portion 143 extends from the main body portion 141 toward the electrode assembly 12, the end of the first connection portion 143 toward the main body portion 141 does not extend beyond the first position limit portion 112.

[0129] The end of the first connection portion 143 that faces away from the main body portion 141 does not extend beyond the first position limit portion 112, that is, the end of the first connection portion 143 that faces away from the main body portion 141 is located within the first position limit portion 112, and as can be understood, in the thickness direction Z of the end cap 13, the end of the first connection portion 143 that faces away from the main body portion 141 is closer to the electrode assembly 12 than the end face of the end of the first position limit portion 112 that faces away from the electrode assembly 12.

[0130] In this embodiment, since one end of the first connecting portion 143 that faces away from the main body portion 141 does not exceed the first position limiting portion 112, the first connecting portion 143 is less likely to interfere with the end cap 13, and airtightness between the end cap 13 and the case 11 is ensured.

[0131] In some embodiments, continuing with reference to Figure 7, the first connecting portion 143 is welded to the inner circumferential surface 1121 of the first position limiting portion 112, the inner circumferential surface 1121 of the first position limiting portion 112 has a boundary position 1121a, and the radial dimension of the inner circumferential surface 1121 of the first position limiting portion 112 gradually increases from the boundary position 1121a to both ends of the inner circumferential surface 1121 of the first position limiting portion 112. In the direction in which the first connecting portion 143 extends toward the electrode assembly 12 of the main body portion 141, one end of the first connecting portion 143 toward the main body portion 141 extends beyond the boundary position 1121a.

[0132] In the above explanation, both ends of the inner circumferential surface 1121 refer to both ends of the inner circumferential surface 1121 in the thickness direction Z of the end cap 13.

[0133] The radial dimension of the inner circumferential surface 1121 of the first position limiting portion 112 gradually increases from the boundary position 1121a to both ends of the inner circumferential surface 1121 of the first position limiting portion 112, resulting in a constricted structure where the inner circumferential surface 1121 of the first position limiting portion 112 is larger at both ends and smaller in the center. Exemplarily, the intersection of the inner circumferential surface 1121 of the first position limiting portion 112 and its axial cross-section is arc-shaped, and the axial cross-section is parallel to the thickness direction Z of the end cap 13.

[0134] In this embodiment, one end of the first connecting portion 143 that faces away from the main body portion 141 extends beyond the boundary position 1121a, thereby forming a welding groove between the outer circumferential surface of the first connecting portion 143 and the inner circumferential surface 1121 of the first position limiting portion 112, which facilitates welding and fixing the first connecting portion 143 and the first position limiting portion 112.

[0135] For example, in Figure 7, the welded portion 17 formed by welding the first connecting portion 143 to the first position limiting portion 112 is located within a weld groove formed between the first connecting portion 143 and the first position limiting portion 112.

[0136] In some embodiments, referring to Figure 8, which is a partial view of a battery cell 10 according to a further embodiment of the present application, the first connection portion 143 may include an extending segment 1431 and a position limiting segment 1432. The extending segment 1431 is connected to the main body portion 141 and extends from the main body portion 141 in a direction away from the electrode assembly 12, with at least a portion of the extending segment 1431 extending to the inner circumference side of the first position limiting portion 112. The position limiting segment 1432 is connected to the extending segment 1431 and is welded to the first position limiting portion 112, abutting against the side of the first position limiting portion 112 away from the electrode assembly 12.

[0137] The extending segment 1431 is the portion of the first connection portion 143 that extends into the interior of the first position limiting portion 112, and the position limiting segment 1432 is the welded portion between the first connection portion 143 and the first position limiting portion 112. At least a portion of the extending segment 1431 extends to the inner circumference of the first position limiting portion 112, and the position limiting segment 1432 abuts against the side of the first position limiting portion 112 that is away from the electrode assembly 12, thereby engaging the first connection portion 143 with the first position limiting portion 112, and causing the main body portion 141 of the current collector member 14 to be in close contact with the first position limiting portion 112. Exemplarily, the extending segment 1431 is a cylindrical structure, and the position limiting segment 1432 is an annular structure provided at one end of the extending segment 1431 away from the main body portion 141. The position limiting segment 1432 may be welded to the first position limiting portion 112 by through welding.

[0138] In this embodiment, the position limiting segment 1432 is welded to the first position limiting portion 112, abutting against the side of the first position limiting portion 112 that is opposite to the electrode assembly 12. The position limiting segment 1432 performs a position limiting function, increasing the rigidity after the current collector member 14 is welded to the first position limiting portion 112, and increasing the contact area between the current collector member 14 and the first position limiting portion 112, thereby increasing the overcurrent area between the case 11 and the current collector member 14.

[0139] In some embodiments, referring to Figures 5 to 8, the first position limiting portion 112 is an annular structure extending along the circumferential direction of the case 11. Such a structure of the first position limiting portion 112 is easy to mold and manufacture, and the first position limiting portion 112 can perform a limiting effect on the end cap 13 over its entire circumference, ensuring the position limiting capability of the first position limiting portion 112 relative to the end cap 13.

[0140] In some embodiments, a roller groove 113 is provided at a position corresponding to the first position limiting portion 112 on the outer surface of the case 11.

[0141] In the process of forming the roller groove 113, the case 11 forms a first position limiting portion 112 at a position corresponding to the roller groove 113, thereby simplifying the molding process of the first position limiting portion 112. After the first position limiting portion 112 is formed by the process related to the roller groove 113, the radial dimension of the inner circumferential surface 1121 of the first position limiting portion 112 gradually increases from the boundary position 1121a to both ends of the inner circumferential surface 1121 of the first position limiting portion 112.

[0142] In embodiments where the first position limiting portion 112 is an annular structure extending along the circumferential direction of the case 11, the roller groove 113 may be an annular structure extending along the axial direction of the case 11.

[0143] In some embodiments, the battery cell 10 further includes a sealing member 15, and the end cap 13 and the case 11 are sealed together via the sealing member 15 to ensure airtightness between the end cap 13 and the case 11.

[0144] The sealing member 15 may be made of a material such as rubber or plastic.

[0145] In some embodiments, the sealing member 15 is positioned to insulate and isolate the case 11 from the end cap 13. The sealing member 15 performs both sealing and insulating functions between the case 11 and the end cap 13, ensuring airtightness between the end cap 13 and the case 11 while simultaneously reducing the risk of static charge on the end cap 13.

[0146] In some embodiments, the sealing member 15 is positioned to cover the end cap 13 along the circumferential direction of the opening of the case 11. Such a structure enhances the airtightness of the sealing member 15 to the end cap 13 and the case 11, and improves the integration of the sealing member 15 and the case 11. During the assembly process of the battery cell 10, the sealing member 15 may be placed over the end cap 13, and then the end cap 13 and the sealing member 15 may be mounted together as a single unit in the case 11.

[0147] In some embodiments, a second position limiting portion 114 is provided at one end of the opening of the case 11 to restrict the end cap 13 from detaching from the case 11 in a direction away from the electrode assembly 12. In the thickness direction Z of the end cap 13, at least a portion of the sealing member 15 is positioned between the end cap 13 and the second position limiting portion 114 to achieve a sealed connection between the end cap 13 and the case 11.

[0148] The second position limiting portion 114 acts as a limiting force on the end cap 13, thereby preventing the end cap 13 from detaching from the case 11 in a direction away from the electrode assembly 12. The second position limiting portion 114, in conjunction with the first position limiting portion 112, limits the movement of the end cap 13 in the thickness direction Z, thereby restricting the end cap 13 to one end of the case 11 having an opening. At least a portion of the sealing member 15 is located between the end cap 13 and the second position limiting portion 114, thereby achieving a sealed connection between the end cap 13 and the case 11 and ensuring good airtightness between the end cap 13 and the case 11.

[0149] For example, the second position limiting portion 114 may be a flange structure in which a part of the case 11 is folded inward, and the second position limiting portion 114 can be formed at the opening position of the case 11 by folding the case 11. In the process of assembling the battery cell 10, the electrode assembly 12 and the current collector 14 may be housed in the case 11, then a first position limiting portion 112 may be formed by machining a roller groove 113 on the case 11, then the entire end cap 13 and sealing member 15 may be brought into contact with the first position limiting portion 112, and finally the second position limiting portion 114 may be formed by folding the case 11 to limit the end cap 13.

[0150] In some embodiments, the sealing member 15 includes an enclosure 151 and a second connecting portion 152, the second connecting portion 152 being connected to the enclosure 151. At least a portion of the end cap 13 is located within the enclosure 151, and in the thickness direction Z of the end cap 13, the second connecting portion 152 is located between the end cap 13 and the second position limiting portion 114 to achieve a sealed connection between the end cap 13 and the case 11.

[0151] The enclosure 151 is provided to surround the outer circumference of the end cap 13, and the sealing member 15 ensures that the end cap 13 is covered along the circumferential direction of the opening of the case 11. Exemplarily, the end cap 13 causes the enclosure 151 to abut against the inner surface 111 of the case 11, and the enclosure 151 performs a sealing function together with the second position limiting portion 114.

[0152] In this embodiment, at least a portion of the end cap 13 is located inside the enclosure 151, and the second connecting portion 152 is located between the end cap 13 and the second position limiting portion. This simplifies the structure of the sealing member 15, ensuring good airtightness between the end cap 13 and the case 11, while also providing the sealing member 15 with good integration with the end cap 13.

[0153] In some embodiments, the sealing member 15 may further include a third connecting portion 153, which is connected to the enclosure 151 and abuts against the first position limiting portion 112, and the third connecting portion 153 and the second connecting portion 152 abut against both ends of the end cap 13 in the thickness direction Z of the end cap 13, thereby preventing the sealing member 15 from moving relative to the end cap 13 in the thickness direction Z of the end cap 13, and resulting in the sealing member 15 having good integration with the end cap 13.

[0154] For example, both the first connection part 143 and the second connection part 152 have annular structures.

[0155] Furthermore, the embodiment of the present application provides a battery 100 comprising a plurality of battery cells 10 according to any one of the embodiments described above.

[0156] The embodiment of the present application provides an electrical device comprising a battery cell 10 according to any one of the embodiments described above.

[0157] The electrical equipment may be any of the above-mentioned equipment to which the battery 100 is applied.

[0158] Referring also to Figures 4 and 7, the embodiment of the present application further provides a battery cell 10 comprising a case 11, an electrode assembly 12, an end cap 13, and a current collector 14. The case 11 has an opening, and a roller groove 113 is provided on the outer surface of the case 11, and a first position limiting portion 112 is formed in the case 11 at a position corresponding to the roller groove 113, protruding from the inner surface 111 of the case 11. The electrode assembly 12 has a negative electrode tab and a positive electrode tab, and the electrode assembly 12 is housed within the case 11. The end cap 13 is fitted over the opening of the case 11 and is sealed to the case 11, and the first position limiting portion 112 is used to restrict the end cap 13 from moving along the direction facing the electrode assembly 12. The current collector 14 is positioned to connect the negative electrode tab to the case 11, so that the electrode assembly 12 is electrically connected to the case 11. One end of the case 11, away from the end cap 13, is provided with an electrode terminal 16 that is electrically connected to the positive electrode tab.

[0159] Here, the current collector 14 includes a main body 141 and a first connecting portion 143, the main body 141 being located on the side of the first position limiting portion 112 facing the electrode assembly 12 and in contact with the first position limiting portion 112, the first connecting portion 143 being connected to the main body 141 and extending to the inner circumference side of the first position limiting portion 112, the first connecting portion 143 forming a positional alignment with the inner circumferential surface 1121 of the first position limiting portion 112 and the first connecting portion 143 being welded to the inner circumferential surface 1121 of the first position limiting portion 112. The inner circumferential surface 1121 of the first connecting portion 143 has a boundary position 1121a, and the radial dimension of the inner circumferential surface 1121 gradually increases from the boundary position 1121a to both ends of the inner circumferential surface 1121. In the direction in which the first connecting portion 143 extends from the main body portion 141 toward the electrode assembly 12, one end of the first connecting portion 143 toward the main body portion 141 exceeds the boundary position 1121a but does not exceed the first position limiting portion 112. The main body portion 141 has an inner surface 1411 facing the electrode assembly 12 and an outer surface 1412 toward the electrode assembly 12. The first connecting portion 143 is a convex portion extending from the outer surface 1412 of the main body portion 141 toward the electrode assembly 12. The current collector member 14 is provided with a recess 144 that is recessed into the convex portion toward the electrode assembly 12 from the inner surface 1411 of the main body portion 141. Both the convex portion and the recess 144 are annular structures that extend along the circumferential direction of the first position limiting portion 112.

[0160] In such a battery cell 10, welding between the current collector 14 and the case 11 can be easily achieved before the end cap 13 is fitted over the opening of the case 11. As a result, electrical connection between the electrode assembly 12 and the case 11 is easily realized, a stable and large overcurrent area is secured between the current collector 14 and the case 11, and the operating performance of the battery cell 10 is ensured.

[0161] The embodiments of this application provide a method for manufacturing a battery cell 10. Referring to Figure 9, Figure 9 is a flowchart of a method for manufacturing a battery cell 10 according to some embodiments of this application. The manufacturing method includes the following steps.

[0162] S100: Provides a case 11 having an opening.

[0163] S200: Provides electrode assembly 12.

[0164] S300: Provides end cap 13.

[0165] S400: Provides a current collector 14.

[0166] S500: The current collector 14 is connected to the electrode assembly 12.

[0167] S600: The electrode assembly 12 and the current collector member 14 are housed inside the case 11.

[0168] S700: The end cap 13 is fitted over the opening of the case 11, and the end cap 13 and the case 11 are sealed together so that the current collector 14 is positioned on the side of the electrode assembly 12 facing the end cap 13.

[0169] Here, the case 11 and the electrode assembly 12 are electrically connected by the current collector 14.

[0170] In the method described above, the order of steps S100, S200, S300, and S400 is not specified. For example, step S400 may be performed first, followed by step S300, then step S200, and then step S100.

[0171] Regarding the related structures of the battery cell 10 manufactured by the manufacturing method described above, you may refer to the battery cell 10 described in each of the above-described embodiments, but we will omit that here.

[0172] In some embodiments, the manufacturing method further includes welding the current collector 14 to the case 11 from the inside of the case 11 before fitting the end cap 13 over the opening.

[0173] Embodiments of the present application further provide a manufacturing facility 2000 for battery cells 10. Referring to Figure 10, Figure 10 is a schematic diagram of the structure of a manufacturing facility 2000 for battery cells 10 according to some embodiments of the present application. The manufacturing facility 2000 comprises a first supplying device 2100, a second supplying device 2200, a third supplying device 2300, a fourth supplying device 2400, and an assembly device 2500.

[0174] A first supplying device 2100 is used to supply a case 11 having an opening. A second supplying device 2200 is used to supply an electrode assembly 12. A third supplying device 2300 is used to supply an end cap 13. A fourth supplying device 2400 is used to supply a current collector 14. An assembly device 2500 is used to connect the current collector 14 to the electrode assembly 12, and is further used to house the electrode assembly 12 and the current collector 14 inside the case 11, and is further used to cover and fit the end cap 13 over the opening and to seal the end cap 13 and the case 11 so that the current collector 14 is positioned on the side of the electrode assembly 12 facing the end cap 13. Here, the case 11 and the electrode assembly 12 are electrically connected by the current collector 14.

[0175] Regarding the related structures of the battery cells 10 manufactured by the manufacturing equipment 2000 according to the above embodiment, you may refer to the battery cells 10 according to each embodiment described above, but we will omit that here.

[0176] Furthermore, the embodiments and features of the embodiments of this application can be combined with each other, as long as there is no contradiction.

[0177] The embodiments described above are merely illustrative of the technical concept of the present application and do not limit it. Those skilled in the art will know that the present application may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present application should all be within the scope of protection. [Explanation of Symbols]

[0178] 10-Battery Cells 11-Case 111-Inner surface 112-First position limiting section 1121-Inner surface 1121a-boundary position 113-Roller groove 114-Second position limiting section 12-Electrode Assembly 13-End Cap 14-Current collector 141 - Main body 1411-Inner 1412-exterior 142-Elastic part 143-First connection section 1431 - Extended Segment 1432 - Location-restricted segment 144-recess 15-Sealing member 151-Enclosure 152 - Second connection section 153 - Third connection point 16-electrode terminal 17-Welded section 20-Enclosure 21-Part 1 22-Second part 100-battery 200-Controller 300-Motor 1000-vehicle 2000-Manufacturing equipment 2100-First supply device 2200 - Second supplying device 2300 - Third supply device 2400 - Fourth supply device 2500 - Assembly Equipment Z-thickness direction

Claims

1. A case having an opening, An electrode assembly housed within the aforementioned case, An end cap that covers the opening and is fitted to the case, and is sealed to the case, The case comprises a current collector member housed within the case, positioned on the side of the electrode assembly facing the end cap, welded to the case, and arranged to connect the case and the electrode assembly so that the electrode assembly is electrically connected to the case. The inner surface of the case has a protruding first position limiting portion, which is an annular structure extending along the circumferential direction of the case, and is intended to restrict the movement of the end cap along the direction facing the electrode assembly, and the current collecting member is a battery cell welded to the first position limiting portion.

2. The battery cell according to claim 1, wherein the current collector and the case are welded together, and a welded portion is formed inside the case for fixing the current collector and the case.

3. The aforementioned current collector member is Located on the side of the first position limiting portion facing the electrode assembly, and including a main body portion for connecting the electrode assembly, The battery cell according to claim 1, wherein the first position limiting portion is used to limit the main body portion from detaching from the case in a direction opposite to the electrode assembly.

4. The battery cell according to claim 3, wherein the main body portion abuts against the side of the first position limiting portion facing the electrode assembly and is welded to the first position limiting portion.

5. The aforementioned current collector member is The battery cell according to claim 3, further comprising an elastic portion connected to the main body portion, in contact with the first position limiting portion, and welded to the first position limiting portion.

6. The battery cell according to claim 5, wherein the elastic portion is an elastic sheet provided on the main body portion by being folded.

7. The aforementioned current collector member is The battery cell according to claim 3, further comprising a first connecting portion connected to the main body, at least a portion of which extends to the inner circumference of the first position limiting portion and is welded to the first position limiting portion.

8. The battery cell according to claim 7, wherein the first connection portion is a protrusion extending from the main body portion in a direction away from the electrode assembly, and the protrusion is used to form a positional alignment with the inner circumferential surface of the first position limiting portion.

9. The main body has an inner surface facing the electrode assembly and an outer surface facing away from the electrode assembly, and the protrusion extends from the outer surface in a direction away from the electrode assembly. The battery cell according to claim 8, wherein the current collecting member further includes a recess that is recessed into the convex portion along a direction away from the inner surface and away from the electrode assembly.

10. The battery cell according to claim 9, wherein both the convex portion and the concave portion are annular structures extending along the circumferential direction of the first position limiting portion.

11. The battery cell according to any one of claims 7 to 10, wherein, in the direction in which the first connection portion extends from the main body portion toward the electrode assembly, one end of the first connection portion toward the main body portion does not exceed the first position limiting portion.

12. The first connecting portion is welded to the inner circumferential surface of the first position limiting portion, the inner circumferential surface has a boundary position, and the radial dimension of the inner circumferential surface gradually increases from the boundary position to both ends of the inner circumferential surface. The battery cell according to any one of claims 7 to 11, wherein in the direction in which the first connection portion extends from the main body portion toward the electrode assembly, one end of the first connection portion toward the main body portion exceeds the boundary position.

13. The first connection part is, An extending segment connected to the main body, extending from the main body in a direction away from the electrode assembly, and at least a portion of which extends to the inner circumference side of the first position limiting portion, A position limiting segment connected to the extended segment and welded to the first position limiting portion, abutting against the side of the first position limiting portion that is opposite to the electrode assembly, A battery cell according to claim 7, including the following:

14. A battery cell according to any one of claims 1 to 13, wherein a roller groove is provided at a position corresponding to the first position limiting portion on the outer surface of the case.

15. The aforementioned battery cell further comprises a sealing member, The battery cell according to any one of claims 1 to 14, wherein the end cap and the case are sealed and connected by the sealing member.

16. The battery cell according to claim 15, wherein the sealing member is arranged to insulate and isolate the case and the end cap.

17. The battery cell according to claim 15 or 16, wherein the sealing member is arranged to cover the end cap along the circumferential direction of the opening.

18. The case is provided with a second position limiting portion at one end of the opening to prevent the end cap from detaching from the case in a direction away from the electrode assembly. The battery cell according to any one of claims 15 to 17, wherein at least a portion of the sealing member is positioned between the end cap and the second position limiting portion in the thickness direction of the end cap to achieve a sealed connection between the end cap and the case.

19. The sealing member includes an enclosure and a second connecting portion connected to the enclosure, The battery cell according to claim 18, wherein at least a portion of the end cap is located within the enclosure, and the second connection portion is located between the end cap and the second position limiting portion in the thickness direction of the end cap to achieve a sealed connection between the end cap and the case.

20. The battery cell according to any one of claims 1 to 19, wherein the electrode assembly includes a positive electrode tab and a negative electrode tab, and the positive electrode tab and the negative electrode tab are located at opposite ends of the electrode assembly.

21. The battery cell according to claim 20, wherein the current collector is arranged to electrically connect the negative electrode tab and the case.

22. The battery cell according to claim 20 or 21, wherein an electrode terminal is provided at one end of the case away from the end cap, the electrode terminal is insulatedly connected to the case, and is electrically connected to the positive electrode tab.

23. A battery comprising a plurality of battery cells according to any one of claims 1 to 22.

24. An electrical device comprising a battery cell according to any one of claims 1 to 22.

25. To provide a case having an opening, To provide an electrode assembly, To provide end caps, To provide a current collector, Connecting the current collector to the electrode assembly, The electrode assembly and the current collector are housed in the case, The end cap is fitted over the opening, and the end cap and the case are sealed together so that the current collector is positioned on the side of the electrode assembly facing the end cap. A method for manufacturing a battery cell, which includes welding the current collector to the case inside the case, A method for manufacturing a battery cell, wherein the case and the electrode assembly are electrically connected by the current collector, the inner surface of the case has a protruding first position limiting portion which is an annular structure extending along the circumferential direction of the case and limits the movement of the end cap along the direction facing the electrode assembly, and the current collector is welded to the first position limiting portion.

26. A first providing device for providing a case having an opening, A second supplying apparatus for providing an electrode assembly, A third supplying device for providing end caps, A fourth supplying device for providing a current collector, A battery cell manufacturing apparatus comprising an assembly device used for connecting a current collector to the electrode assembly, housing the electrode assembly and the current collector within the case, fitting the end cap over the opening and sealing the end cap and the case so that the current collector is positioned on the side of the electrode assembly facing the end cap, and welding the current collector to the case inside the case, A battery cell manufacturing apparatus wherein the case and the electrode assembly are electrically connected by the current collector, the inner surface of the case has a first position limiting portion protruding from it, which is an annular structure extending along the circumferential direction of the case, and the end cap is limited to restricting movement along the direction facing the electrode assembly, and the current collector is welded to the first position limiting portion.

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