Battery cell, battery, electrical equipment, and manufacturing method and equipment for battery cell

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, entitled "Battery Cell, Battery, Electrical Equipment, and Method and Apparatus for Manufacturing Battery Cell," the entire contents of which are incorporated herein by reference.

[0002] The present application relates to the technical field of batteries, and in particular to battery cells, batteries, electrical equipment, and methods and equipment for manufacturing battery cells. [Background technology]

[0003] The batteries commonly used in vehicles are generally lithium-ion batteries, a type of secondary battery that has advantages such as small size, high energy density, high power density, many cycles, and long storage time.

[0004] A battery cell typically comprises a case for housing an electrode assembly and an electrolyte, and an electrode assembly that generally includes a positive electrode sheet and a negative electrode sheet, and generates electrical energy by transferring metal ions (e.g., lithium ions) between the positive electrode sheet and the negative electrode sheet.

[0005] In a typical battery cell, the electrode assembly needs to be electrically connected to the case so that the case functions as the positive output terminal or negative output terminal of the battery cell, and currently, it is relatively difficult to electrically connect the electrode assembly to the case. Summary of the Invention [Problem to be solved by the invention]

[0006] The embodiments of the present application provide a battery cell, a battery, an electrical device, and a method and device for manufacturing a battery cell that can more easily connect an electrode assembly to a case. [Means for solving the problem]

[0007] According to a first aspect, an embodiment of the present application provides a battery cell including a case having an opening, an electrode assembly housed within the case, an end cap fitted over the opening and hermetically connected to the case, and a current collecting member housed within the case, located on a 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 technical solution, the current collecting member 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 collecting member, the end cap is fitted over the opening of the case, and the end cap is hermetically connected to the case. With this structure, during 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, which makes it easier to electrically connect the electrode assembly and the case.

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

[0010] In the above technical solution, the current collecting member is welded to the case, the connection method between the current collecting member and the case is simple, the strength of the connection between the current collecting member and the case can be ensured, and a stable overcurrent can be realized between the current collecting member and the case.

[0011] In some embodiments, the current collecting member and the case are welded together to form a weld located inside the case to secure the current collecting member to the case.

[0012] In the above technical solution, the weld formed by welding the current collecting member to the case is located inside the case, reducing the risk of damage to the outer layer structure of the case due to the weld being located outside the case when welding the current collecting member to the case, reducing the risk of corrosion of the case, and improving the service life of the battery cell.

[0013] In some embodiments, a first position limiting portion is protruded on an inner surface of the case to limit movement of the end cap along a direction facing the electrode assembly, and the current collecting member is welded to the first position limiting portion.

[0014] In the above technical solution, the first position limiting portion has a position limiting effect on the end cap, and the first position limiting portion can limit the end cap from moving along the direction facing the electrode assembly. The current collecting member is welded to the first position limiting portion that has a limiting effect on the end cap, which effectively utilizes the first position limiting portion and is advantageous for welding and fixing the current collecting member.

[0015] In some embodiments, the current collecting member is located on a side of the first position limiting portion facing the electrode assembly and includes a main body portion for connecting the electrode assembly, and the first position limiting portion is used to limit the main body portion from being detached from the case along a direction away from the electrode assembly.

[0016] In the above technical solution, the first position limiting portion has a limiting effect on the main body portion, and can limit the main body portion from being detached from the case along a direction away from the electrode assembly; the first position limiting portion can isolate the end cap and the main body portion, and the main body portion is less likely to affect the sealing between the end cap and the case, thereby ensuring airtightness between the end cap and the case.

[0017] In some embodiments, the body portion is welded to the first position limiting portion against a side of the first position limiting portion facing the electrode assembly.

[0018] In the above technical solution, the main body portion is abutted against the side of the first position limiting portion facing the electrode assembly and welded to the first position limiting portion, so that the entire current collecting member has good strength after being fixed to the first position limiting portion, and the contact area between the current collecting member and the first position limiting portion is increased, thereby increasing the overcurrent area between the case and the current collecting member.

[0019] In some embodiments, the current collecting member further includes an elastic portion connected to the body portion, abutting the first position limiting portion and welded to the first position limiting portion.

[0020] In the above technical solution, the elastic portion of the collecting member abuts against the first position limiting portion and is welded to the first position limiting portion, and the elastic portion is elastically deformable in accordance with changes in the distance between the main body portion and the first position limiting portion, thereby reducing the risk of poor electrical connection between the main body portion and the electrode assembly due to the electrode assembly moving within the case due to vibration of the battery cell.

[0021] In some embodiments, the elastic portion is an elastic sheet folded over the body portion.

[0022] In the above technical solution, the elastic part is an elastic sheet folded onto the main body, which has a simple structure and excellent deformation ability.

[0023] In some embodiments, the current collecting member further includes a first connection portion connected to the main body portion, at least a portion of which extends to an inner peripheral side of the first position limiting portion, and which is welded to the first position limiting portion.

[0024] In the above technical proposal, at least a portion of the first connection portion of the collecting member extends to the inner side of the first position limiting portion, and the first connection portion is welded to the first position limiting portion, reducing the difficulty of welding between the collecting member and the first position limiting portion.

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

[0026] In the above technical solution, the first connection part is a protrusion that is aligned with the inner peripheral surface of the first position limiting part, and the protrusion is aligned with the inner peripheral surface of the first position limiting part, reducing the risk of the current collecting member shaking during the welding process between the first connection part and the first position limiting part, lowering the difficulty of welding, and increasing the strength after welding the first connection part to the first position limiting part. At the same time, the contact area between the case and the current collecting member is increased, thereby increasing the overcurrent area between the case and the current collecting member.

[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 from the outer surface along a direction facing away from the electrode assembly, and the current collecting member further includes a recess recessed into the convex portion along a direction facing away from the electrode assembly from the inner surface.

[0028] In the above technical solution, the current collecting member is provided with a recess that is recessed into the protrusion along a direction from the inner surface of the main body toward the electrode assembly, which reduces the material of the current collecting member and reduces manufacturing costs, and increases the deformation ability of the protrusion so that the protrusion elastically abuts against the first position limiting portion, ensuring good contact between the protrusion and the first position limiting portion.

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

[0030] In the above technical solution, the protrusion and the recess are both annular structures extending along the circumferential direction of the first position limiting portion, which allows the protrusion to have better deformation ability.

[0031] In some embodiments, in a direction in which the first connection portion extends from the main body portion toward the electrode assembly, one end of the first connection portion facing away from the main body portion does not extend beyond the first position limit portion.

[0032] In the above technical solution, the end of the first connection facing the main body does not exceed the first positional limiting portion, so that the first connection portion is less likely to interfere with the end cap, and the sealing between the end cap and the case is ensured.

[0033] In some embodiments, the first connection portion is welded to an 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 a direction in which the first connection portion extends along a direction away from the main body portion toward the electrode assembly, one end of the first connection portion away from the main body portion exceeds the boundary position.

[0034] In the above technical proposal, one end of the first connection part facing away from the main body part extends beyond the boundary position, thereby forming a weld groove between the outer peripheral surface of the first connection part and the first position limiting part, making it easier to weld and fix the first connection part to the first position limiting part, and ensuring strength after welding the first connection part to the first position limiting part.

[0035] In some embodiments, the first connection portion includes an extension segment connected to the main body portion, extending from the main body portion along a direction away from the electrode assembly, and at least a portion of which extends to an inner peripheral side of the first position limiting portion, and a position limiting segment connected to the extension segment, abutting 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 technical solution, the position limiting segment abuts against the side of the first position limiting part facing away from the electrode assembly and is welded to the first position limiting part, so that the position limiting segment performs a limiting function, increases the strength of the current collecting member after welding to the first position limiting part, and increases the contact area between the current collecting member and the first position limiting part, thereby increasing the overcurrent area between the case and the current collecting member.

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

[0038] In the above technical solution, the first position limiting part has an annular structure, which is easy to mold and manufacture, and the first position limiting part exerts a limiting effect on the end cap around the entire circumference, thereby ensuring the position limiting ability of the first position limiting part against the end cap.

[0039] In some embodiments, a roller groove is provided on the outer surface of the case at a position corresponding to the first position limiting portion.

[0040] In the above technical solution, a roller groove is provided on the outer surface of the case, and in the process of forming the roller groove, the case forms a first position limiting portion at a position corresponding to the roller groove, which can simplify the molding process of the first position limiting portion.

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

[0042] In the above technical solution, in order to ensure the sealing between the end cap and the case, the end cap and the case are hermetically connected by a sealing member.

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

[0044] In the above technical solution, the case and the end cap are insulated and isolated by the sealing member, which performs a sealing function between the case and the end cap while also performing an insulating function, thereby ensuring the airtightness between the end cap and the case while reducing the risk of static electricity in the end cap.

[0045] In some embodiments, the sealing member is positioned to cover the end cap circumferentially around the opening.

[0046] In the above technical solution, the sealing member covers the end cap along the circumferential direction of the opening of the case, which on the one hand enhances the sealing ability of the sealing member to the end cap and the case, and on the other hand improves the integration of the sealing member with the case. During the process of assembling the battery cell, after the sealing member covers the end cap, the end cap and the sealing member may be integrated and attached to the case.

[0047] In some embodiments, the case is provided at one end of the opening with a second position limiting portion for limiting detachment of the end cap from the case along 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 so as to achieve a sealed connection between the end cap and the case.

[0048] In the above technical solution, the second position limiting portion acts on the end cap to limit the end cap from being separated from the case along the direction away from the electrode assembly, and at least a part of the sealing member is located between the end cap and the second position limiting portion to realize a hermetic connection between the end cap and the case and ensure good sealing between the end cap and the case.

[0049] In some embodiments, the sealing member includes an enclosure and a second connection portion connected to the enclosure, 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 a second position limiting portion in a thickness direction of the end cap so as to achieve a sealed connection between the end cap and a case.

[0050] In the above technical solution, the sealing member includes an enclosure and a second connecting portion which are connected to each other, 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 the second position limiting portion, so that the structure of the sealing member is simple, and good sealing between the end cap and the case is achieved, while providing good integration between the sealing member and the end cap.

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

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

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

[0054] In some embodiments, the method further includes welding the current collecting member to the case from inside the case prior to fitting the end cap over the opening.

[0055] According to a fifth aspect, an embodiment of the present application provides a battery cell manufacturing facility including a first providing device for providing a case having an opening, a second providing device for providing an electrode assembly, a third providing device for providing an end cap, a fourth providing device for providing a current collecting member, and an assembly device used for connecting the current collecting member to the electrode assembly, further housing the electrode assembly and the current collecting member in the case, and further fitting the end cap over the opening and sealingly connecting the end cap and the case such that the current collecting member is located on a side of the electrode assembly facing the end cap, wherein the case and the electrode assembly are electrically connected by the current collecting member. [Brief description of the drawings]

[0056] In order to more clearly describe the technical solutions of the embodiments of the present application, the following briefly describes the drawings to be used in the embodiments of the present application. The drawings below only illustrate some embodiments of the present application, and should not be considered as limiting the scope. It should be understood that a person skilled in the art can further obtain other related drawings based on these drawings without creative efforts.

[0057] [Figure 1] 1 is a structural schematic diagram of a vehicle according to some embodiments of the present application. [Diagram 2] FIG. 1 is a structural schematic diagram of a battery according to some examples of the present application. [Diagram 3] FIG. 2 is an exploded view of a battery cell according to some embodiments of the present application. [Figure 4] FIG. 4 is a cross-sectional view of the battery cell shown in FIG. [Diagram 5] FIG. 2 is a partial view of a battery cell according to some embodiments of the present application. [Figure 6] FIG. 2 is a partial view of a battery cell according to some other embodiments of the present application. [Figure 7] FIG. 5 is a partial view of the battery cell shown in FIG. [Figure 8] 1 is a partial view of a battery cell according to some further embodiments of the present application. [Figure 9] 2 is a flowchart of a method for manufacturing a battery cell according to some embodiments of the present application. [Figure 10] FIG. 2 is a structural schematic diagram of a battery cell manufacturing facility according to some embodiments of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0058] In order to make the objectives, technical solutions and advantages of the present application clearer, the following will refer to the drawings in the embodiments of the present application to describe in detail the technical solutions of the embodiments of the present application. Obviously, the embodiments described herein are only a part of the embodiments of the present application, not all of the embodiments of the present application. Based on the embodiments of the present application, all other embodiments that can be obtained by those skilled in the art without creative efforts are within the scope of the present application.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application. The terms "include" and "have" and any variations thereof in the specification, claims and brief description of the drawings of this application are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification, claims or drawings of this application are used to distinguish different objects, not to indicate a particular order or subordinate relationship.

[0060] The term "embodiment" as used herein means that any combination of particular features, structures, or characteristics described in the embodiment may be included in at least one embodiment of the present application. The appearances of the term in various places in the present specification are not necessarily all referring to the same embodiment, nor are they intended to be mutually exclusive, independent, or alternative embodiments of other embodiments.

[0061] In the description of this application, unless otherwise specified or limited, the technical terms "mounted," "connected," "connected," "attached," etc. should be understood in a broad sense. For example, they may be fixedly connected, detachably connected, or integrated, may be directly connected, indirectly connected via an intermediate medium, or may be internally connected between two elements. Those skilled in the art can understand the specific meaning of these terms in this application according to the specific circumstances.

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

[0063] As used herein, the term "plurality" means two or more (including two).

[0064] In the present application, the battery cell may include a lithium ion secondary battery, a lithium ion primary battery, a lithium sulfur battery, a sodium lithium ion battery, a sodium ion battery, or a magnesium ion battery, and the embodiments of the present application are not limited thereto. The battery cell may be cylindrical, flat, rectangular, or other shapes, and the embodiments of the present application are not limited thereto. Battery cells are generally broadly divided into three types, namely, cylindrical cells, square cells, and pouch cells, depending on the packaging method, and the embodiments of the present application are not limited thereto.

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

[0066] The battery cell includes an electrode assembly consisting of a positive electrode sheet, a negative electrode sheet, and a separator, and an electrolyte. The battery cell is mainly operated by the movement of metal ions between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer, the positive electrode active material layer is applied to the surface of the positive electrode collector, the positive electrode collector not coated with the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer, and the positive electrode collector not coated with the positive electrode active material layer is a positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive electrode collector may be aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, lithium manganate, etc. The negative electrode sheet includes a negative electrode collector and a negative electrode active material layer, the negative electrode active material layer is applied to the surface of the negative electrode collector, the negative electrode collector not coated with the negative electrode active material layer protrudes from the negative electrode collector coated with the negative electrode active material layer, and the negative electrode collector not coated with the negative electrode active material layer is a negative electrode tab. The material of the negative electrode collector may be copper, and the negative electrode active material may be carbon or silicon. The positive electrode tab is formed by stacking a plurality of pieces, and the negative electrode tab is formed by stacking a plurality of pieces, so that a large current can pass without melting. The material of the separator may be PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly may be a wound type structure or a stacked type structure, and the embodiment of the present application is not limited thereto.

[0067] In a typical battery cell, the electrode assembly needs to be electrically connected to the case so that the case functions as the positive or negative output terminal of the battery cell, and currently, it is relatively difficult to electrically connect the electrode assembly to the case.

[0068] The inventors found that, in a battery cell, the case has a hollow structure with an opening at the top end, 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 determine the condition of the welding between the electrode assembly and the bottom wall of the case.

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

[0070] In such a battery cell, the current collecting member provides electrical connection between the electrode assembly and the case, and when assembling the battery cell, the current collecting member can be connected to the case inside the case. After the current collecting member is connected to the electrode assembly and case, an end cap is fitted over the opening of the case and hermetically connected to the case, making it even easier to electrically connect the electrode assembly to the case.

[0071] The battery cells described in the embodiments of the present application are applicable to batteries and electrical equipment that uses batteries.

[0072] The electrical equipment may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, or an electric tool. The vehicle may be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or a range-extender electric vehicle, etc. The spacecraft includes an airplane, a rocket, a space shuttle, a spaceship, etc. The electric toy includes a stationary or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric plane toy. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool, a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, an electric shavings, etc. There is no particular limitation on the electrical equipment in the embodiments of the present application.

[0073] In the following embodiments, for convenience of explanation, electrical equipment will be described using a vehicle as an example.

[0074] Referring to Fig. 1, Fig. 1 is a structural schematic diagram of a vehicle 1000 according to some embodiments of the present application. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom, head, or rear of the vehicle 1000. The battery 100 is applied to power the vehicle 1000, and for example, the battery 100 can be used as an 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 control power supply from the battery 100 to the motor 300, for example, power for operation when the vehicle 1000 is started, navigated, or driven.

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

[0077] In some embodiments, referring to Fig. 2, Fig. 2 is a structural schematic diagram of a battery 100 according to some embodiments of the present application, and the battery 100 includes a plurality of battery cells 10. The plurality of battery cells 10 may be connected in series, in parallel, or in series-parallel. A series-parallel connection means that the plurality of battery cells 10 are connected in series and in parallel.

[0078] In some embodiments, the battery 100 may further include a bus bar member, and multiple battery cells 10 can be electrically connected to each other via the bus bar member to achieve a series connection, a parallel connection, or a series-parallel connection of the multiple battery cells 10.

[0079] The busbar members may be metallic conductors, such as, for example, copper, iron, aluminum, steel, aluminum alloys, and the like.

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

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

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

[0083] The case 11 is a component for housing the electrode assembly 12, and may have a hollow structure with one end open or both ends open. The case 11 may be made of a variety of materials, such as copper, iron, aluminum, steel, and aluminum alloy. The case 11 may have various shapes, such as a cylinder or a rectangular parallelepiped. Exemplarily, in FIG. 3, the case 11 is a cylinder, and the battery cell 10 shown in FIG. 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 a tab, the tab extending from the main body so as to protrude from an end 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 a positive electrode sheet, a separator, and a negative electrode sheet. The main body may be a laminated structure formed by stacking a positive electrode sheet, a separator, and a negative electrode sheet.

[0085] The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer applied to 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 applied to both opposing sides of the negative electrode current collector. The main body is a portion of the electrode assembly 12 corresponding to an area where the active material layer is applied to the sheet, and the tab is a portion where the active material layer is not applied to the sheet. The tab may be divided into a positive electrode tab and a negative electrode tab, and the positive electrode tab and the negative electrode tab protrude from both ends of the main body, respectively.

[0086] The end cap 13 is a part that covers and fits over the opening of the case 11 to isolate 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 the end cap 13 and the case 11 together define a sealed space for accommodating the electrode assembly 12, the electrolyte, and the current collecting member 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 further, if the case 11 has a cylindrical structure, the end cap 13 has a disk-like structure that fits the case 11. The material of the end cap 13 may also be of various kinds, and the end cap 13 may be a metal material such as copper, iron, aluminum, steel, aluminum alloy, etc., and the material of the end cap 13 may be the same as or different from the material of the case 11.

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

[0088] The current collecting member 14 is a component that connects the case 11 and the electrode assembly 12 to realize an electrical connection between the electrode assembly 12 and the case 11 so that the case 11 functions as one output pole of the battery cell 10. In an embodiment in which the electrode assembly 12 is electrically connected to an electrode terminal 16, the positive electrode tab or the negative electrode tab of the electrode assembly 12 may be electrically connected to the electrode terminal 16 via one current collecting member 14; for example, the negative electrode tab of the electrode assembly 12 is electrically connected to the case 11 via one current collecting member 14, and the positive electrode tab of the electrode assembly 12 is electrically connected to the electrode terminal 16 via another current collecting member 14.

[0089] Current collecting member 14 may be a metallic conductor, such as, for example, copper, iron, aluminum, steel, an aluminum alloy, or the like.

[0090] The sealing member 15 is a component provided between the end cap 13 and the case 11, and provides a hermetic 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 FIG. 4, FIG. 4 is a cross-sectional view of the battery cell 10 shown in FIG. 3. An embodiment of the present application provides a battery cell 10 including a case 11, an electrode assembly 12, an end cap 13, and a current collecting member 14. The case 11 has an opening. The electrode assembly 12 is housed in the case 11. The end cap 13 is fitted over the opening and hermetically connected to the case 11. The current collecting member 14 is housed in the case 11 and is located on the side of the electrode assembly 12 facing the end cap 13, and the current collecting member 14 is arranged 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 collecting member 14 is a component that realizes an electrical connection between the electrode assembly 12 and the case 11, and the current collecting member 14 is connected to the case 11 while being connected to the electrode assembly 12. The current collecting member 14 is connected to the electrode assembly 12, and the current collecting member 14 may be connected to the positive electrode tab of the electrode assembly 12 or may be connected to the negative electrode tab of the electrode assembly 12. The connection between the current collecting member 14 and the electrode assembly 12 may be, for example, by welding the current collecting member 14 to the positive electrode tab or the negative electrode tab of the electrode assembly 12, so that the two are connected and fixed, or, for example, by simply abutting the current collecting member 14 against the positive electrode tab or the negative electrode tab of the electrode assembly 12, so that the two are in contact with each other. The connection between the current collecting member 14 and the case 11 may be, for example, by welding the current collecting member 14 to the case 11, so that the two are connected and fixed, or,, for example, by simply abutting the current collecting member 14 against the positive electrode tab or the negative electrode tab of the electrode assembly 12, so that the two are in contact with each other.

[0093] In the embodiment of the present application, the current collecting member 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 collecting member 14, the end cap 13 is fitted over the opening of the case 11, and the end cap 13 is hermetically connected to the case 11. The battery cell 10 having such a structure realizes the electrical connection between the electrode assembly 12 and the case 11 by the current collecting member 14, the current collecting member 14 can be connected to the case 11 inside the case 11, and after the current collecting member 14 is connected to the electrode assembly 12 and the case 11, the end cap 13 is fitted over the opening of the case 11 and hermetically connected to the case 11, which makes the electrical connection between the electrode assembly 12 and the case 11 easier.

[0094] In a typical battery cell 10, the bottom wall of the case 11 is welded to the tab, and therefore the bottom wall of the case 11 is likely to be damaged in the process of welding the bottom wall of the case 11 to the tab, resulting in leakage and affecting the performance of the battery cell 10. On the other hand, in the embodiment of the present application, the electrode assembly 12 and the case 11 are electrically connected by the current collecting member 14, and the end cap 13 is hermetically connected to the case 11, and the electrode assembly 12 is not directly connected to the end cap 13, so that the battery cell 10 is less likely to experience leakage from the end cap 13 side.

[0095] Illustratively, the current collecting member 14 is connected between the case 11 and a negative electrode tab of the electrode assembly 12 so that the case 11 functions as a negative output electrode of the battery cell 10. The electrode terminal 16 at one end of the case 11 remote from the end cap 13 is electrically connected to a positive electrode tab of the electrode assembly 12 so that the electrode terminal 16 functions as a positive output electrode of the battery cell 10.

[0096] In some embodiments, the current collecting member 14 is welded to the case 11. The connection method between the current collecting member 14 and the case 11 is simple, the connection between the current collecting member 14 and the case 11 is strong, and a stable overcurrent is realized between the current collecting member 14 and the case 11.

[0097] When welding current collecting member 14 to case 11, welding may be performed outside case 11; for example, current collecting member 14 may be welded to case 11 from outside case 11 by a full penetration welding method, or current collecting member 14 may be welded to case 11 inside case 11. When welding is performed outside case 11, weld 17 formed by welding current collecting member 14 to case 11 is located outside case 11, whereas when welding is performed inside case 11, weld 17 formed by welding current collecting member 14 to case 11 is located inside case 11.

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

[0099] The welded portion 17 serves to fix the current collecting member 14 and the case 11, that is, the current collecting member 14 is fixed to the case 11 via the welded portion 17. The welded portion 17 may be solder that connects the current collecting member 14 and the case 11, or may be a fused portion formed by fusing the current collecting member 14 and the case 11 together.

[0100] For example, if the material of case 11 is steel, when welded portion 17 formed by welding current collecting member 14 to case 11 is located outside case 11, the outer protective layer of case 11 is likely to be damaged during the process of welding current collecting member 14 to case 11, and corrosion is likely to occur.

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

[0102] 4, in some embodiments, a first position limiting portion 112 is provided on the inner surface 111 of the case 11 to protrude therefrom, and the first position limiting portion 112 is used to limit the movement of the end cap 13 along a direction facing the electrode assembly 12. The current collecting member 14 is welded to the first position limiting portion 112.

[0103] The inner surface 111 of the case 11 refers to the inner surface of a side wall of the case 11 extending along the thickness direction Z of the end cap 13. The first position limiting portion 112 is provided in a protruding manner on the inner surface 111 of the case 11, and is a structure for limiting movement of the end cap 13 along a direction facing the electrode assembly 12. The first position limiting portion 112 and the case 11 may be integrally molded, or may be joined after being molded separately.

[0104] In this embodiment, the first position limiting portion 112 has a limiting effect on the end cap 13, and can limit the movement of the end cap 13 along the direction facing the electrode assembly 12. The current collecting member 14 is welded to the first position limiting portion 112 that has a limiting effect on the end cap 13, and effective use of the first position limiting portion 112 is advantageous for welding and fixing the current collecting member 14.

[0105] 5, which is a partial view of a battery cell 10 according to some embodiments of the present application. The current collecting member 14 includes a body portion 141 for connecting to the electrode assembly 12, and the body portion 141 is located on a side of the first position limiting portion 112 facing the electrode assembly 12, and the first position limiting portion 112 is used to limit the body portion 141 from being detached from the case 11 along a direction away from the electrode assembly 12.

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

[0107] The first position limiting portion 112 has a limiting effect on the main body portion 141, and can limit the main body portion 141 from being detached from the case 11 along a direction away from the electrode assembly 12. The first position limiting portion 112 can isolate the end cap 13 and the main body portion 141, and the main body portion 141 is less likely to affect the sealing between the end cap 13 and the case 11, thereby ensuring airtightness between the end cap 13 and the case 11.

[0108] In some embodiments, with continued reference to FIG. 5, the body portion 141 abuts the side of the first position limiting portion 112 facing the electrode assembly 12 and is welded to the first position limiting portion 112 .

[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 surface of the first position limiting portion 112 facing the electrode assembly 12, and the first position limiting portion 112 acts 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 portion 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, so that the entire current collecting member 14 has good strength after being fixed to the first position limiting portion 112, and the contact area between the current collecting member 14 and the first position limiting portion 112 is increased, thereby increasing the overcurrent area between the case 11 and the current collecting member 14.

[0111] For example, in FIG. 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 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 surface 1121 of the first position limiting portion 112.

[0112] In some embodiments, refer to Fig. 6, which is a partial view of a battery cell 10 according to some other embodiments of the present application. The current collecting member 14 may include an elastic portion 142 connected to the body portion 141 and abutting against the first position limiting portion 112 and welded to the first position limiting portion 112.

[0113] The elastic portion 142 is an elastically deformable portion of the current collecting 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 may be molded separately and then joined. The current collecting member 14 may have one or more elastic portions 142. When the current collecting member 14 has multiple elastic portions 142, the multiple elastic portions 142 may be distributed at intervals on the main body portion 141 along the circumferential direction of the main body portion 141.

[0114] In this embodiment, the elastic portion 142 of the collecting member 14 abuts against the first position limiting portion 112 and is welded to the first position limiting portion 112, and 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 the electrode assembly 12 moving within the case 11 due to vibration of the battery cell 10.

[0115] In some embodiments, still referring to FIG. 6, the elastic portion 142 is an elastic sheet that is folded onto the main body portion 141, and such an elastic portion 142 has a simple structure, excellent deformation ability, 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 resilient portion 142 may have other structures, for example, a spring structure in which the resilient portion 142 is connected to the body portion 141 .

[0117] In some embodiments, refer to Fig. 7, which is a partial view of the battery cell 10 shown in Fig. 4. The current collecting member 14 may further include a first connection portion 143, the first connection portion 143 is connected to the body portion 141, at least a portion of the first connection portion 143 extends to the inner periphery side 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 a portion where the current collecting member 14 is welded to the first position limiting portion 112, and at least a portion of this portion extends to the inner circumferential 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 portion of the first connection portion 143 extends to the inner circumferential side of the first position limiting portion 112. In other words, at least a portion of the first connection portion 143 extends within the space defined by the inner circumferential surface 1121 of the first position limiting portion 112.

[0119] In this embodiment, the first connection portion 143 is welded to the first position limiting portion 112, and since a portion of the first connection portion 143 of the current collecting member 14 extends to the inner peripheral side of the first position limiting portion 112, the first connection portion 143 may be welded directly to the first position limiting portion 112, thereby reducing the difficulty of welding between the current collecting member 14 and the first position limiting portion 112.

[0120] When the first connection portion 143 of the current collecting member 14 is welded to the first position limiting portion 112, the main body portion 141 of the current collecting 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 Fig. 7, in order to increase the overcurrent area between the current collecting 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, with continued reference to FIG. 7 , the first connection portion 143 is a convex portion extending from the main body portion 141 in a direction away from the electrode assembly 12, and the convex portion is used to form a positioning alignment with the inner surface 1121 of the first position limiting portion 112.

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

[0123] In this embodiment, the first connection portion 143 is a convex portion that is aligned with the inner circumferential surface 1121 of the first position limiting portion 112, and since the convex portion is aligned with the inner circumferential surface 1121 of the first position limiting portion 112, the risk of vibration of the current collecting member 14 during the welding process between the first connection portion 143 and the first position limiting portion 112 is reduced, the difficulty of welding is reduced, and the strength after welding the first connection 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 collecting member 14 is increased, thereby increasing the overcurrent area between the case 11 and the current collecting member 14.

[0124] 7 , in some embodiments, the main body portion 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 convex portion extends from the outer surface 1412 of the main body portion 141 along a direction facing away from the electrode assembly 12. The current collecting member 14 further includes a recess 144 recessed into the convex portion along a direction facing away from the electrode assembly 12 from the inner surface 1411 of the main body portion 141.

[0125] Providing the recess 144 in the current collecting member 14, on the one hand, reduces the material of the current collecting member 14 and reduces manufacturing costs, and on the other hand, increases the deformation ability of the convex portion so that the convex portion elastically abuts against the first position limiting portion 112, ensuring good contact between the convex portion and the first position limiting portion 112.

[0126] In some embodiments, both the protrusion and recess 144 are annular structures that extend along the circumferential direction of the first position limiter 112 .

[0127] Since the convex portion and the concave portion 144 are both annular structures, the convex portion has better deformation ability. When the convex portion receives a radial force from the first position limiting portion 112, the convex portion can contract and deform to a central position, so that the convex portion and the first position limiting portion 112 are relatively closely matched, and the convex portion and the first position limiting portion 112 are in good contact with each other.

[0128] In some embodiments, still referring to FIG. 7 , in the direction in which the first connection portion 143 extends from the main body portion 141 along a direction away from the electrode assembly 12, the end of the first connection portion 143 that faces away from the main body portion 141 does not extend beyond the first position limiting portion 112.

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

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

[0131] 7, in some embodiments, the first connection 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 a direction in which the first connection portion 143 extends along a direction of the main body portion 141 that is away from the electrode assembly 12, one end of the first connection portion 143 that is away from the main body portion 141 exceeds the boundary position 1121a.

[0132] In the above description, the two ends of the inner circumferential surface 1121 refer to the two 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, so that the inner circumferential surface 1121 of the first position limiting portion 112 has a constricted structure that is larger at both ends and smaller at the center. Illustratively, 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 connection portion 143 that faces away from the main body portion 141 exceeds the boundary position 1121a, thereby forming a weld groove between the outer peripheral surface of the first connection portion 143 and the inner peripheral surface 1121 of the first position limiting portion 112, making it easier to weld the first connection portion 143 and the first position limiting portion 112 together.

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

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

[0137] The extension segment 1431 is a portion of the first connection portion 143 that extends into the first position limiting portion 112, and the position limiting segment 1432 is a welded portion between the first connection portion 143 and the first position limiting portion 112. At least a portion of the extension segment 1431 extends to the inner periphery side of the first position limiting portion 112, and the position limiting segment 1432 abuts against the side of the first position limiting portion 112 facing away from the electrode assembly 12, so that the first connection portion 143 is engaged with the first position limiting portion 112, and the main body portion 141 of the current collecting member 14 abuts tightly against the first position limiting portion 112. Exemplarily, the extension segment 1431 is a cylindrical structure, and the position limiting segment 1432 is an annular structure provided at one end of the extension segment 1431 that is away from the main body portion 141. The position limiting segment 1432 may be welded to the first position limiting portion 112 by a pierce weld.

[0138] In this embodiment, the position limiting segment 1432 abuts against the side of the first position limiting portion 112 facing away from the electrode assembly 12 and is welded to the first position limiting portion 112. The position limiting segment 1432 performs a position limiting function, increases the strength of the current collecting member 14 after it is welded to the first position limiting portion 112, and increases the contact area between the current collecting member 14 and the first position limiting portion 112, thereby increasing the overcurrent area between the case 11 and the current collecting member 14.

[0139] 5 to 8, in some embodiments, the first position limiting portion 112 has an annular structure extending along the circumferential direction of the case 11. The first position limiting portion 112 having such a structure is easy to manufacture by molding, and the first position limiting portion 112 can exert a limiting effect on the end cap 13 over the entire circumference, ensuring the position limiting ability of the first position limiting portion 112 relative to the end cap 13.

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

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

[0142] In an embodiment in which 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 hermetically connected via the sealing member 15 to ensure hermeticity 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 disposed so as to insulate the case 11 from the end cap 13. The sealing member 15 performs an insulating function while performing a sealing function between the case 11 and the end cap 13, thereby ensuring the hermeticity between the end cap 13 and the case 11, while at the same time reducing the risk of static electricity being generated in the end cap 13.

[0146] In some embodiments, the sealing member 15 is disposed so as to cover the end cap 13 along the circumferential direction of the opening of the case 11. Such a structure, on the one hand, enhances the sealing performance of the sealing member 15 with respect to the end cap 13 and the case 11, and on the other hand, improves the integration of the sealing member 15 with the case 11. During the process of assembling the battery cell 10, after the sealing member 15 covers the end cap 13, the end cap 13 and the sealing member 15 may be attached to the case 11 as a unit.

[0147] In some embodiments, a second position limiting portion 114 is provided at one end of the opening of the case 11 to limit detachment of the end cap 13 from the case 11 along 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 located between the end cap 13 and the second position limiting portion 114 to achieve a hermetic connection between the end cap 13 and the case 11.

[0148] The second position limiting portion 114 acts to limit the end cap 13, thereby limiting the end cap 13 from being detached from the case 11 in a direction away from the electrode assembly 12, and 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 of the end cap 13, thereby limiting the end cap 13 to one end having an opening of the case 11. At least a part of the sealing member 15 is located between the end cap 13 and the second position limiting portion 114, thereby realizing a hermetic connection between the end cap 13 and the case 11 and ensuring good sealing between the end cap 13 and the case 11.

[0149] For example, the second position limiting portion 114 may have 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 back the case 11. In the process of assembling the battery cell 10, the electrode assembly 12 and the current collecting member 14 may be housed in the case 11, then the case 11 may be machined to form a roller groove 113 to form the first position limiting portion 112, then the end cap 13 and the sealing member 15 as a whole may be brought into contact with the first position limiting portion 112, and finally the case 11 may be folded back to form the second position limiting portion 114 to restrict the end cap 13.

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

[0151] The enclosure 151 is provided to surround the outer periphery of the end cap 13, and the sealing member 15 covers the end cap 13 along the circumferential direction of the opening of the case 11. For example, the end cap 13 abuts the enclosure 151 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 within the enclosure 151, and the second connection portion 152 is located between the end cap 13 and the second position limiting portion, so that the structure of the sealing member 15 is simple and good sealing performance is achieved between the end cap 13 and the case 11 while the sealing member 15 has good integration with the end cap 13.

[0153] In some embodiments, the sealing member 15 may further include a third connection portion 153, which is connected to the enclosure 151 and abuts against the first position limiting portion 112, and the third connection portion 153 and the second connection portion 152 abut against both ends of the end cap 13 in the thickness direction Z of the end cap 13, respectively, so that the sealing member 15 cannot move in the thickness direction Z of the end cap 13 relative to the end cap 13, and the sealing member 15 has good integrity with the end cap 13.

[0154] Illustratively, the first connecting portion 143 and the second connecting portion 152 are both ring-shaped structures.

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

[0156] An embodiment of the present application provides an electric device including the battery cell 10 according to any one of the above-described embodiments.

[0157] The electrical equipment may be any of the equipment described above in which the battery 100 is applied.

[0158] 4 and 7, the embodiment of the present application further provides a battery cell 10 including a case 11, an electrode assembly 12, an end cap 13, and a current collecting member 14. The case 11 has an opening, a roller groove 113 is provided on the outer surface of the case 11, and a first position limiting portion 112 protruding from the inner surface 111 of the case 11 is formed at a position corresponding to the roller groove 113 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 in the case 11. The end cap 13 is fitted over the opening of the case 11 and is hermetically connected to the case 11, and the first position limiting portion 112 is used to limit the movement of the end cap 13 along a direction facing the electrode assembly 12. The current collecting member 14 is arranged to connect the negative electrode tab and the case 11 to electrically connect the electrode assembly 12 to the case 11. An electrode terminal 16 is provided at one end of the case 11 remote from the end cap 13 and electrically connected to the positive electrode tab.

[0159] Here, the current collecting member 14 includes a main body portion 141 and a first connecting portion 143, the main body portion 141 is located on the side of the first position limiting portion 112 facing the electrode assembly 12 and abuts against the first position limiting portion 112, the first connecting portion 143 is connected to the main body portion 141, the first connecting portion 143 extends to the inner peripheral side of the first position limiting portion 112, the first connecting portion 143 forms a positional alignment with the inner peripheral surface 1121 of the first position limiting portion 112, and the first connecting portion 143 is welded to the inner peripheral surface 1121 of the first position limiting portion 112. The inner peripheral surface 1121 of the first connecting portion 143 has a boundary position 1121a, and the radial dimension of the inner peripheral surface 1121 gradually increases from the boundary position 1121a to both ends of the inner peripheral surface 1121. In the direction in which the first connection portion 143 extends from the main body portion 141 in the direction away from the electrode assembly 12, one end of the first connection portion 143 facing away from the main body portion 141 exceeds the boundary position 1121a, and 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 facing away from the electrode assembly 12, the first connection portion 143 is a convex portion extending from the outer surface 1412 of the main body portion 141 in the direction away from the electrode assembly 12, and the current collecting member 14 is provided with a concave portion 144 recessed into the convex portion from the inner surface 1411 of the main body portion 141 in the direction away from the electrode assembly 12. Both the convex portion and the concave portion 144 are annular structures extending along the circumferential direction of the first position limiting portion 112.

[0160] In such a battery cell 10, the current collecting member 14 and the case 11 can be easily welded together 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 achieved, a stable and large overcurrent area is secured between the current collecting member 14 and the case 11, and the usability of the battery cell 10 is ensured.

[0161] The embodiments of the present application provide a method for manufacturing a battery cell 10. Referring to Fig. 9, Fig. 9 is a flow chart of a method for manufacturing a battery cell 10 according to some embodiments of the present application. The method includes the following steps:

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

[0163] S200: Provide an electrode assembly 12.

[0164] S300: Provide end cap 13.

[0165] S400: Provide a current collecting member 14.

[0166] S500: Connect the current collecting member 14 to the electrode assembly 12.

[0167] S600: The electrode assembly 12 and the current collecting member 14 are housed in 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 hermetically connected so that the current collecting member 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 a current collecting member 14 .

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

[0171] Note that, for the relevant structure of the battery cell 10 manufactured by the manufacturing method according to the embodiment described above, reference may be made to the battery cell 10 according to each embodiment described above, and therefore further description is omitted here.

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

[0173] The embodiment of the present application further provides a manufacturing equipment 2000 for the battery cell 10. Referring to Fig. 10, Fig. 10 is a structural schematic diagram of the manufacturing equipment 2000 for the battery cell 10 according to some embodiments of the present application. The manufacturing equipment 2000 includes a first providing apparatus 2100, a second providing apparatus 2200, a third providing apparatus 2300, a fourth providing apparatus 2400 and an assembly apparatus 2500.

[0174] The first providing device 2100 is used to provide a case 11 having an opening. The second providing device 2200 is used to provide an electrode assembly 12. The third providing device 2300 is used to provide an end cap 13. The fourth providing device 2400 is used to provide a current collecting member 14. The assembly device 2500 is used to connect the current collecting member 14 to the electrode assembly 12, and the assembly device 2500 is further used to house the electrode assembly 12 and the current collecting member 14 in the case 11, and the assembly device 2500 is further used to fit the end cap 13 over the opening and hermetically connect the end cap 13 and the case 11, so that the current collecting member 14 is located 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 collecting member 14.

[0175] Note that, for the relevant structure of the battery cell 10 manufactured by the manufacturing facility 2000 according to the above embodiment, the battery cell 10 according to each of the above-mentioned embodiments may be referred to, and will not be described here.

[0176] Furthermore, unless there is a contradiction, the embodiments and features in the embodiments of the present application can be combined with each other.

[0177] The above embodiments are merely for illustrating the technical solution of the present application, and are not intended to limit the present application. Those skilled in the art may have various modifications and variations of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application should be included within the protection scope of the present application. [Explanation of symbols]

[0178] 10-Battery Cell 11-Case 111-Inner surface 112-First position limiting part 1121-Inner surface 1121a-boundary position 113-Roller groove 114-Second position limiting part 12-Electrode Assembly 13-End Cap 14- Current collecting member 141 - Main body 1411-Inside 1412-exterior 142-Elastic part 143-First Connection 1431-Extended Segment 1432 - Position restriction segment 144-Recess 15-Sealing member 151 - Enclosure 152-Second connection 153-Third Connector 16-electrode terminal 17- Welded parts 20-Case 21-Part 1 22-Second part 100-battery 200-Controller 300-Motor 1000-Vehicle 2000-Manufacturing equipment 2100-First provider 2200-Second provider 2300-Third provider 2400-Fourth provider 2500-Assembly Equipment Z-thickness direction

Claims

1. a case having an opening; an electrode assembly housed within the case; an end cap fitted over the opening and sealingly connected to the case; a current collecting member housed within the case, located on a 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.

2. The battery cell according to claim 1 , wherein the current collecting member is welded to the case.

3. 3 . The battery cell according to claim 2 , wherein the current collecting member and the case are welded to each other, forming a weld portion located inside the case for fixing the current collecting member and the case together.

4. a first position limiting portion is provided on an inner surface of the case to limit movement of the end cap along a direction facing the electrode assembly; The battery cell according to any one of claims 1 to 3, wherein the current collecting member is welded to the first position limiting portion.

5. The current collecting member is a body portion for connecting the electrode assembly, the body portion being located on a side of the first position limiting portion facing the electrode assembly; The battery cell according to claim 4 , wherein the first position limiting portion is used to limit detachment of the main body from the case along a direction away from the electrode assembly.

6. The battery cell according to claim 5 , wherein the main body portion is welded to the first position limiting portion by abutting against a side of the first position limiting portion facing the electrode assembly.

7. The current collecting member is The battery cell according to claim 5 , further comprising an elastic portion connected to the body portion, abutting against the first position limiting portion and welded to the first position limiting portion.

8. The battery cell according to claim 7 , wherein the elastic portion is an elastic sheet that is folded and provided on the main body portion.

9. The current collecting member is The battery cell according to claim 5 , further comprising a first connection portion connected to the main body portion, at least a portion of which extends to an inner periphery of the first position limiting portion, and which is welded to the first position limiting portion.

10. 10. The battery cell according to claim 9, wherein the first connection portion is a protrusion extending from the main body portion in a direction away from the electrode assembly, the protrusion being used to form a positioning alignment with an inner circumferential surface of the first position limiting portion.

11. the main body portion has an inner surface facing the electrode assembly and an outer surface facing away from the electrode assembly, the protrusion extending from the outer surface along a direction facing away from the electrode assembly, The battery cell according to claim 10 , wherein the current collecting member further includes a recess recessed into the protrusion from the inner surface along a direction away from the electrode assembly.

12. The battery cell according to claim 11 , wherein the protrusion and the recess are both annular structures extending in a circumferential direction of the first position limiting portion.

13. A battery cell as described in any one of claims 9 to 12, wherein in a direction in which the first connection portion extends from the main body portion along a direction away from the electrode assembly, one end of the first connection portion that faces away from the main body portion does not extend beyond the first position limiting portion.

14. the first connection portion is welded to an inner circumferential surface of the first position limiting portion, the inner circumferential surface has a boundary position, and a radial dimension of the inner circumferential surface gradually increases from the boundary position to both ends of the inner circumferential surface; A battery cell as described in any one of claims 9 to 13, wherein in a direction in which the first connection portion extends from the main body portion along a direction away from the electrode assembly, one end of the first connection portion away from the main body portion extends beyond the boundary position.

15. The first connection portion is an extension segment connected to the main body portion, extending from the main body portion along a direction away from the electrode assembly, and at least a portion of the extension segment extending to an inner circumferential side of the first position limiting portion; a position limiting segment connected to the extension segment and welded to the first position limiting portion while abutting against the side of the first position limiting portion facing away from the electrode assembly; 10. The battery cell of claim 9 .

16. The battery cell according to any one of claims 4 to 15, wherein the first position limiting portion has an annular structure extending along a circumferential direction of the case.

17. The battery cell according to any one of claims 4 to 16, wherein a roller groove is provided on the outer surface of the case at a position corresponding to the first position limiting portion.

18. The battery cell further includes a sealing member. The battery cell according to any one of claims 1 to 17, wherein the end cap and the case are hermetically connected by the sealing member.

19. The battery cell of claim 18 , wherein the sealing member is disposed to insulate the case and the end cap.

20. The battery cell according to claim 18 or 19, wherein the sealing member is disposed so as to cover the end cap along a circumferential direction of the opening.

21. the case is provided with a second position limiting portion at one end of the opening for limiting detachment of the end cap from the case along a direction away from the electrode assembly; A battery cell as described in any one of claims 18 to 20, wherein at least a portion of the sealing member is positioned between the end cap and the second position limiting portion in a thickness direction of the end cap so as to achieve a sealed connection between the end cap and the case.

22. the sealing member includes an enclosure and a second connection portion connected to the enclosure; 22. The battery cell of claim 21, 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 a thickness direction of the end cap so as to achieve a sealed connection between the end cap and the case.

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

24. An electrical installation comprising the battery cell according to any one of claims 1 to 22.

25. providing a case having an opening; Providing an electrode assembly; Providing an end cap; Providing a current collecting member; connecting a current collecting member to the electrode assembly; housing the electrode assembly and the current collecting member in the case; fitting the end cap over the opening and sealingly connecting the end cap and the case such that the current collecting member is located on a side of the electrode assembly facing the end cap, The case and the electrode assembly are electrically connected by the current collecting member.

26. Prior to fitting the end cap over the opening, the method includes:

26. The method of claim 25, further comprising welding the current collecting member to the case from inside the case.

27. a first providing device for providing a case having an opening; a second delivery device for delivering the electrode assembly; a third application device for applying an end cap; a fourth providing device for providing a current collecting member; and an assembly device used to connect a current collecting member to the electrode assembly, to house the electrode assembly and the current collecting member in the case, and to fit the end cap over the opening and to hermetically connect the end cap and the case such that the current collecting member is located on a side of the electrode assembly facing the end cap, A battery cell manufacturing facility in which the case and the electrode assembly are electrically connected by the current collecting member.

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