Battery cell, battery, power consumption device, and method and device for manufacturing battery cell

Abstract

The embodiments of the present application provide a battery cell, a battery, a power consumption device, and a manufacturing method and device for a battery cell, which belong to the technical field of batteries. Here, the battery cell includes a case, an electrode assembly, an end cap, and a current collecting part. The case has an opening. The electrode assembly is accommodated in the case. The end cap is placed over the opening and is sealably connected to the case. The current collecting part is accommodated in the case and located on the side of the electrode assembly facing the end cap, and the current collecting part is configured to connect the case and the electrode assembly such that the electrode assembly is electrically connected to the case. In the assembly process of the battery cell, the current collecting part can be connected to the case inside the case, and the robustness after the current collecting part and the case are connected can be ensured, and after the current collecting part is connected to the electrode assembly and the case, the end cap is placed over the opening of the case and sealably connected to the case, which facilitates the electrical connection between the electrode assembly and the case.

Description

[Technical field]

[0001] The present application relates to the field of battery technology, and in particular to battery cells, batteries, power consuming devices, and methods and devices for manufacturing battery cells. [Background technology]

[0002] The batteries commonly used in vehicles are generally lithium ion batteries, which are rechargeable batteries and have the advantages of small volume, high energy density, high power density, many cycles, and long storage time.

[0003] A battery cell typically includes a case and an electrode assembly. The case is used to house the electrode assembly and an electrolyte. The electrode assembly typically includes a positive electrode plate and a negative electrode plate, and generates electrical energy by transferring metal ions (e.g., lithium ions) between the positive electrode plate and the negative electrode plate.

[0004] For a typical battery cell, the electrode assembly needs to be electrically connected to the case so that the case serves as the positive output terminal or the negative output terminal of the battery cell, and currently, it is not easy to achieve the electrical connection between the electrode assembly and the case. Summary of the Invention [Problem to be solved by the invention]

[0005] The embodiments of the present application provide a battery cell, a battery, a power consuming device, and a method and apparatus for manufacturing a battery cell, which can more easily achieve electrical connection between an electrode assembly and a case. [Means for solving the problem]

[0006] According to a first aspect, an embodiment of the present application provides a battery cell, the battery cell including: a case having an opening; an electrode assembly housed in the case; an end cap that covers the opening and is sealingly connected to the case; and a current collecting component housed in the case and located on a side of the electrode assembly facing the end cap, the current collecting component being configured to connect the case and the electrode assembly such that the electrode assembly is electrically connected to the case.

[0007] In the above technical solution, the current collecting part is located on the side facing the end cap of the electrode assembly, the electrode assembly and the case are electrically connected by the current collecting part, the end cap is placed over the opening of the case, and the end cap is sealed and connected to the case. With this structure, during the assembly process of the battery cell, the current collecting part can be connected to the case inside the case, and the robustness after the current collecting part and the case are connected can be ensured. After the current collecting part is connected to the electrode assembly and the case, the end cap is placed over the opening of the case and sealed and connected to the case, which further facilitates the electrical connection between the electrode assembly and the case.

[0008] In some embodiments, the current collecting piece is connected to an inner surface of the case.

[0009] In the above technical solution, the current collecting part is connected to the inner surface of the case, so that the current collecting part and the case have a large contact area, which can effectively improve the fastness of the connection between the current collecting part and the case.

[0010] In some embodiments, an outer surface of the end cap and an inner surface of the case are positioned opposite each other, at least a portion of the current collecting component is located between the outer surface of the end cap and the inner surface of the case, and the end cap is configured to press a portion of the current collecting component against the inner surface of the case.

[0011] In the above technical solution, at least a portion of the current collecting part is located between the outer surface of the end cap and the inner surface of the case, and the end cap presses a portion of the current collecting part against the inner surface of the case, so that the current collecting part is in close contact with the case and the robustness of the connection between the current collecting part and the case is improved.

[0012] In some embodiments, the current collecting part includes a first connection portion and a second connection portion, at least a portion of the first connection portion is located between the end cap and the electrode assembly in a thickness direction of the end cap, the first connection portion is configured to be connected to the electrode assembly, the second connection portion is connected to the first connection portion and extends from the first connection portion along the thickness direction of the end cap away from the electrode assembly, and the second connection portion is configured to be connected to the case.

[0013] In the above technical solution, the current collecting part includes a first connection part and a second connection part connected to each other, and in the thickness direction of the end cap, at least a part of the first connection part is located between the end cap and the electrode assembly to facilitate the connection between the first connection part and the electrode assembly. The second connection part extends from the first connection part along the thickness direction of the end cap away from the electrode assembly to facilitate the connection between the second connection part and the case. The overall structure of the current collecting part is simple and easy to mold and manufacture.

[0014] In some embodiments, the second connecting portion is a ring structure that is connected to an outer edge of the first connecting portion.

[0015] In the above technical solution, the second connecting part has a ring-shaped structure connected to the outer edge of the first connecting part, which is easy to mold and manufacture, and the second connecting part and the case have a large contact area.

[0016] In some embodiments, the case has a limit portion at one end of the opening, the limit portion being configured to restrict removal of the case along a direction in which the end cap moves away from the electrode assembly.

[0017] In the above technical solution, a limiting portion is provided at one end of the opening of the case, and the limiting portion acts as a limiting portion for restricting the end cap from being detached from the case in the direction away from the electrode assembly.

[0018] In some embodiments, in a thickness direction of the end cap, at least a portion of the end cap is located between the limit portion and the current collecting piece, and the limit portion and the current collecting piece collectively limit movement of the end cap in the thickness direction of the end cap.

[0019] In the above technical solution, in the thickness direction of the end cap, at least a part of the end cap is located between the limit portion and the current collecting part, and both the limit portion and the current collecting part can play a limiting role on the end cap, restricting the movement of the end cap in the thickness direction.

[0020] In some embodiments, the inner surface of the case includes a step surface, and in the thickness direction of the end cap, at least a portion of the end cap is located between the limit portion and the step surface, and the limit portion and the step surface collectively limit movement of the end cap in the thickness direction of the end cap.

[0021] In the above technical solution, in the thickness direction of the end cap, at least a part of the end cap is located between the limit portion and the step surface of the case, and both the limit portion and the step surface can play a limiting role on the end cap, restricting the movement of the end cap in the thickness direction.

[0022] In some embodiments, the limit is an annular structure.

[0023] In the above technical solution, the limit part has an annular structure, which is easy to mold and manufacture, and the entire circumference of the limit part plays a limiting role against the end cap, so that the limiting ability of the limit part against the end cap can be ensured.

[0024] In some embodiments, the limiting portion is a folded structure that folds a portion of the case inward.

[0025] In the above technical solution, the limiting portion is a folded structure in which a part of the case is folded inward, that is, the limiting portion can be formed at the opening position of the case by folding the case, and molding is simple. In the battery cell assembly process, the current collecting part is accommodated in the case and connected to the electrode assembly and the case, and then the end cap is placed over the opening of the case, and finally the limiting portion can be formed by folding the case to restrict the end cap.

[0026] In some embodiments, an inner surface of the case includes a stepped surface, and the current collecting piece abuts against the stepped surface along a direction facing the electrode assembly.

[0027] In the above technical solution, the current collecting part abuts against the step surface of the case along the direction facing the electrode assembly, and the step surface acts as a restraining force on the current collecting part to restrain the current collecting part from moving along the direction facing the electrode assembly. After the current collecting part abuts against the step surface, the current collecting part can be connected to the case, and the installation of the current collecting part can be easily realized.

[0028] In some embodiments, the battery cell further includes a sealing member, and the end cap and the case are sealingly connected by the sealing member.

[0029] In the above technical solution, the end cap and the case are sealed and connected by a sealing member to ensure the sealing performance between the end cap and the case.

[0030] In some embodiments, the seal member is configured to provide insulating isolation between the case and the end cap.

[0031] In the above technical solution, the sealing member insulates and separates the case and the end cap, that is, the sealing member not only performs a sealing function between the case and the end cap, but also performs an insulating function, thereby ensuring the sealing performance between the end cap and the case and reducing the risk of static electricity in the end cap.

[0032] In some embodiments, the seal member is configured to be fitted to the end cap around a circumference of the opening.

[0033] In the above technical solution, the sealing member is coated on the end cap along the circumferential direction of the opening of the case, which on the one hand improves the sealing performance 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 assembly process of the battery cell, the sealing member can be coated on the end cap, and then the end cap and the sealing member can be attached to the case as a whole.

[0034] In some embodiments, the case has a limit portion at one end of the opening, and in the thickness direction of the end cap, at least a portion of the sealing member is located between the end cap and the limit portion to achieve a sealed connection between the end cap and the case.

[0035] In the above technical solution, the limiting portion acts on the end cap to restrict the end cap from being detached from the case along the direction away from the electrode assembly, and at least a portion of the sealing member is located between the end cap and the limiting portion to realize a sealing connection between the end cap and the case and ensure good sealing between the end cap and the case.

[0036] In some embodiments, the sealing member includes an enclosure and a third connection portion, the third connection portion is connected to the enclosure, at least a portion of the end cap is located within the enclosure, and in a thickness direction of the end cap, the third connection portion is located between the end cap and a limit portion to realize a sealed connection between the end cap and a case.

[0037] In the above technical solution, the sealing member includes an enclosure and a third connecting portion connected to each other, at least a portion of the end cap is located within the enclosure, and the third connecting portion is located between the end cap and the limit portion, the structure of the sealing member is simple, and good sealing between the end cap and the case is realized, and the sealing member and the end cap have very good integration.

[0038] In some embodiments, the electrode assembly includes a first tab, the first tab configured to be connected to the current collecting component, the battery cell further includes an insulating member, the insulating member being located between the first tab and the end cap in a thickness direction of the end cap, and the insulating member covering the first tab along a projection in the thickness direction of the end cap.

[0039] In the above technical solution, in the thickness direction of the end cap, the insulating member is located between the first tab and the end cap, the insulating member covers the first tab along the thickness direction projection of the end cap, and the insulating member serves to separate the end cap and the first tab, thereby reducing the risk of static electricity on the end cap.

[0040] In some embodiments, the electrode assembly includes a body and a first tab, the first tab having a tubular structure, one end of the first tab connected to the body, and the other end of the first tab welded to the current collecting piece.

[0041] In the above technical solution, the first tab of the electrode assembly has a tubular structure, and the end of the first tab away from the body is welded to the current collecting part, such a structure can ensure the robustness of the connection between the first tab and the current collecting part and simplify the connection process between the first tab and the current collecting part.

[0042] In some embodiments, the current collecting piece is welded to the case.

[0043] In the above technical solution, the current collecting part is welded to the case, the connection method between the current collecting part and the case is simple, and the fastness of the connection between the current collecting part and the case can be ensured.

[0044] In some embodiments, the melting point of the current collecting piece is lower than the melting point of the case.

[0045] In the above technical solution, the melting point of the current collecting part is lower than the melting point of the case, so that when the current collecting part is welded to the inside of the case, the case is less likely to be destroyed, and the risk of leakage from the case is effectively reduced.

[0046] In some embodiments, the battery cell further includes a pressure relief mechanism, the pressure relief mechanism disposed in the end cap, and the pressure relief mechanism configured to activate to relieve pressure within the battery cell when a pressure or temperature within the battery cell reaches a threshold value.

[0047] In the above technical solution, the end cap is provided with a pressure relief mechanism, which is activated when the internal pressure or temperature of the battery cell reaches a threshold value to release the internal pressure, thereby improving the safety of the battery cell.

[0048] According to a second aspect, an embodiment of the present application provides a battery, the battery including a battery cell according to any one of the embodiments of the first aspect.

[0049] According to a third aspect, an embodiment of the present application provides a power consumer device, the power consumer device including a battery cell according to any one of the embodiments of the first aspect.

[0050] 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 component; connecting the current collecting component to the electrode assembly; housing the electrode assembly and the current collecting component within the case; connecting the current collecting component to the case such that the electrode assembly is electrically connected to the case; and placing the end cap over the opening and sealingly connecting the end cap to the case, such that the current collecting component is located on a side of the electrode assembly facing the end cap.

[0051] In some embodiments, said connecting the current collecting piece to the case comprises welding the current collecting piece to the case from inside the case, wherein a melting point of the current collecting piece is lower than a melting point of the case.

[0052] In the above technical solution, the melting point of the current collecting part is lower than that of the case, and the current collecting part is welded to the case from the inside of the case, which makes the case less likely to be destroyed and effectively reduces the risk of leakage from the case.

[0053] In some embodiments, the manufacturing method further includes performing a folding process on the case after the end cap is placed over the opening, so that the case forms a limit portion at the end where the opening is located, the limit portion restricting the end cap from detaching from the case along a direction away from the electrode assembly.

[0054] In the above technical solution, after the end cap is placed over the opening of the case, the case is folded back to form a limiting portion at the end of the case where the opening is located, thereby restricting the end cap from being detached from the case in the direction away from the electrode assembly. The limiting portion is formed by folding back, which is simple to implement and can effectively reduce manufacturing costs.

[0055] According to a fifth aspect, an embodiment of the present application further provides a battery cell manufacturing apparatus, the manufacturing apparatus comprising: 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 part, and an assembly device for connecting a current collecting part to the electrode assembly, housing the electrode assembly and the current collecting part in the case, connecting the current collecting part to the case such that the electrode assembly is electrically connected to the case, placing the end cap over the opening, and sealingly connecting the end cap to the case, so that the current collecting part is located on a side of the electrode assembly facing the end cap.

[0056] In order to more clearly explain the technical solutions of the embodiments of the present application, the following briefly introduces drawings that need to be used in the embodiments. It should be understood that the following drawings only illustrate some embodiments of the present application, and should not be regarded as limiting the scope. Those skilled in the art can also obtain other related drawings based on these drawings without exerting creative efforts. [Brief description of the drawings]

[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 embodiments 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] 5 is a partial enlarged view of a portion A of the battery cell shown in FIG. [Figure 6] FIG. 2 is a partial enlarged view of a battery cell according to still other embodiments of the present application. [Figure 7] 1 is a partial enlarged view of a battery cell according to some further embodiments of the present application. [Figure 8] FIG. 5 is a partial view of the battery cell shown in FIG. [Figure 9] FIG. 2 is a partial view of a battery cell according to another embodiment of the present application. [Figure 10] 1 is a flow chart of a method for manufacturing a battery cell according to some embodiments of the present application. [Figure 11] 5 is a flowchart of a method for manufacturing a battery cell according to still other embodiments of the present application. [Figure 12] FIG. 1 is a schematic block diagram of a battery cell manufacturing apparatus 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 embodiments of the present application clearer, the following will clearly describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained based on the embodiments of the present application without the need for creative efforts by those skilled in the art are all within the scope of protection of the present application.

[0059] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those skilled in the art in the technical field of this application, and the terms used in the specification of this application are only for describing specific embodiments and are not intended to limit this application, and the terms "comprises" and "has" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive "comprises". The terms "first", "second", etc. in the specification and claims of this application or the above drawings are not intended to describe a specific order or subordinate relationship, but are intended to distinguish different objects.

[0060] An "embodiment" referred to in this application means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they mutually exclusive separate or alternative embodiments of other embodiments.

[0061] In the description of the present application, it should be explained that unless otherwise clearly defined or limited, the terms "attached", "connected", "connected" and "attached" should be understood in a broad sense, for example, may be a fixed connection, a removable connection, or an integral connection, may be a direct connection, may be an indirect connection through an intermediate medium, or may be communication between the insides of two elements. Those skilled in the art can understand the specific meaning of the above terms in the present application according to the specific situation.

[0062] The term "and / or" in this application merely describes the relationship between related objects and indicates that three relationships may exist, for example, A and / or B may represent three cases: A alone, A and B in combination, and B alone. In addition, the character " / " in this application generally indicates that the related objects before and after are in an "or" relationship.

[0063] In the embodiments of the present application, the same reference numerals represent the same elements, and for the sake of brevity, detailed descriptions of the same elements in different embodiments are omitted. It should be understood that the thickness, length, width, etc. of various elements in the embodiments of the present application shown in the drawings, and the overall thickness, length, width, etc. of the integrated device are illustrative descriptions, and should not be construed as any limitation to the present application.

[0064] The term "plurality" as used herein refers to two or more (including two).

[0065] 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, etc., and the embodiments of the present application are not limited thereto. The battery cell may have a cylindrical shape, a flat shape, a rectangular shape, or other shapes, and the embodiments of the present application are not limited thereto. Battery cells are generally divided into three types, namely, a cylindrical battery cell, a rectangular battery cell, and a pouch battery cell, according to the packaging method, and the embodiments of the present application are not limited thereto.

[0066] The battery referred to in the embodiments of the present application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in the present application may include a battery module or a battery pack. The battery generally includes a housing for packaging one or more battery cells. The housing can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0067] The battery cell includes an electrode assembly and an electrolyte, and the electrode assembly is composed of a positive electrode plate, a negative electrode plate, and a separator. The battery cell mainly operates by the movement of metal ions between the positive electrode plate and the negative electrode plate. The positive electrode plate includes a positive electrode collector and a positive electrode active material layer, and the positive electrode active material layer is coated on the surface of the positive electrode collector. The positive electrode collector without 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 without the positive electrode active material layer is called 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, or lithium manganate, etc. The negative electrode plate includes a negative electrode collector and a negative electrode active material layer, the negative electrode active material layer is coated on 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, etc. In order to ensure that the electrode assembly does not melt even when a large current flows, the number of positive electrode tabs is multiple and stacked, and the number of negative electrode tabs is multiple and stacked. 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.

[0068] The development of battery technology requires simultaneous consideration of a wide range of design factors, such as performance parameters such as energy density, cycle life, discharge capacity, and charge / discharge ratio, as well as battery safety.

[0069] For battery cells, the main safety hazards come from the charging and discharging process, and also from the appropriate environmental temperature design. In order to effectively avoid unnecessary losses, there are generally at least three protection measures for battery cells. Specifically, the protection measures include at least a switch element, a suitable separator material selection, and a pressure relief mechanism. The switch element is an element that can stop the battery from charging or discharging when the temperature or resistance inside the battery cell reaches a certain threshold. The separator is for separating the positive and negative plates, and can automatically dissolve the micro-holes on the order of micrometers (and even nanometers) attached thereon when the temperature rises to a certain value, so that metal ions cannot pass through the separator, and the internal reaction of the battery cell is stopped.

[0070] The pressure relief mechanism is an element or member that operates to release the internal pressure or temperature when the internal pressure or temperature of the battery cell reaches a certain threshold. The threshold design varies according to design needs. The threshold may depend on one or more of the materials of the positive electrode plate, the negative electrode plate, the electrolyte, and the separator in the battery cell. The pressure relief mechanism may adopt a form such as an explosion-proof valve, an explosion-proof plate, an air valve, a pressure relief valve, or a safety valve, and may specifically adopt a pressure-sensitive or temperature-sensitive element or structure, that is, when the internal pressure or temperature of the battery cell reaches a certain threshold, the pressure relief mechanism performs an operation, or a fragile structure provided in the pressure relief mechanism is destroyed, thereby forming an opening or channel for releasing the internal pressure or temperature.

[0071] The term "operation" referred to in this application means that the pressure relief mechanism operates or is activated to a certain state, thereby releasing the pressure and temperature inside the battery cell. The operation by the pressure relief mechanism may include, but is not limited to, rupturing, breaking, tearing or opening at least a part of the pressure relief mechanism. When the pressure relief mechanism operates, the high temperature and high pressure material inside the battery cell is discharged from the operating part as a discharge. In this manner, pressure and temperature relief can be generated in the battery cell when the pressure or temperature is controllable, thereby avoiding the occurrence of a potential more serious accident.

[0072] Exhaust from battery cells referred to in this application includes, but is not limited to, electrolyte, melted or split positive and negative plates, separator fragments, high temperature and pressure gases generated by reactions, flames, etc.

[0073] The pressure relief mechanism in a battery cell has an important impact on the safety of the battery. For example, if a phenomenon such as a short circuit or overcharging occurs, thermal runaway may occur inside the battery cell, causing a sudden rise in pressure or temperature. In such a case, the pressure relief mechanism operates to release the internal pressure and temperature to the outside, preventing the battery cell from exploding or catching fire.

[0074] For a typical battery cell, the electrode assembly needs to be electrically connected to the case so that the case serves as the positive output terminal or the negative output terminal of the battery cell, and currently, it is not easy to achieve the electrical connection between the electrode assembly and the case.

[0075] The inventor discovered that in a battery cell, the case has a hollow structure with an open top end, and therefore the electrode assembly is electrically connected to the case; generally, the bottom wall of the case is integrally welded to a tab of the electrode assembly from the outside of the case to achieve electrical connection between the electrode assembly and the case; however, since the tab is located inside the case, it is not possible to determine the welding status between the tab and the bottom wall of the case, and therefore it is not easy to achieve electrical connection between the electrode assembly and the case.

[0076] In view of this, the embodiment of the present application provides a technical solution, in which the electrode assembly and the case are electrically connected by the current collecting part by installing the current collecting part on the side facing the end cap of the electrode assembly, the end cap is placed on the opening of the case, and the end cap is sealed and connected to the case. In the assembly process of the battery cell, the current collecting part can be connected to the case inside the case, and the robustness after the current collecting part and the case are connected can be ensured, and after the current collecting part is connected to the electrode assembly and the case, the end cap is placed on the opening of the case and sealed and connected to the case, which facilitates the electrical connection between the electrode assembly and the case.

[0077] The technical solutions described in the embodiments of the present application are applicable to batteries and power-consuming devices that use batteries.

[0078] The power consumption devices may be vehicles, mobile phones, portable devices, notebook computers, steamships, spacecraft, electric toys and power tools, etc. The vehicles may be fuel oil vehicles, gas vehicles or new energy vehicles, the new energy vehicles may be pure electric vehicles, hybrid vehicles or range extender vehicles, etc., the spacecraft include airplanes, rockets, space shuttles and spaceships, etc., the electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric steamship toys and electric airplane toys, etc., and the electric tools include metal cutting power tools, polishing power tools, assembly power tools and railway power tools, such as electric drills, electric grinders, electric wrenches, electric drivers, electric hammers, hammer drills, concrete vibrators and electric planers, etc. The embodiments of the present application do not particularly limit the above power consumption devices.

[0079] In the following embodiment, for ease of explanation, the power consuming device is a vehicle.

[0080] 1, which is a structural schematic diagram of a vehicle 1000 according to some embodiments of the present application, in which a battery 100 is installed inside the vehicle 1000, and the battery 100 may be installed at the bottom, head or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be an operating power source for the vehicle 1000.

[0081] The vehicle 1000 may further include a controller 200 and a motor 300, where the controller 200 is used to control the battery 100 for powering the motor 300, for example for start-up, navigation and operating power consumption needs of the vehicle 1000 during driving.

[0082] In some embodiments of the present application, the battery 100 can not only serve as the operating power source for the vehicle 1000, but can also serve as the driving power source for the vehicle 1000, providing driving power to the vehicle 1000 in place of or in place of fuel oil or natural gas.

[0083] 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, where 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. Here, the series-parallel connection refers to the plurality of battery cells 10 being connected in series or in parallel.

[0084] In some embodiments, the battery 100 may further include a bus bar member (not shown), and electrical connection between the multiple battery cells 10 can be realized by the bus bar member to realize a series connection, a parallel connection, or a series-parallel connection of the multiple battery cells 10.

[0085] The busbar members may be metallic conductors such as copper, iron, aluminum, steel, aluminum alloys, and the like.

[0086] In some embodiments, the battery cell 10 may further include a housing 20, and the housing 20 is used to accommodate 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 each other to define an accommodation space 23 for accommodating the battery cell 10. Of course, the connection between the first portion 21 and the second portion 22 can be sealed by a sealing element (not shown), and the sealing element may be a sealing ring, a sealant, etc.

[0087] Here, the first part 21 and the second part 22 may have various shapes, for example, a rectangular parallelepiped, a cylindrical body, etc. The first part 21 may have a hollow structure with one side open, and the second part 22 may have a hollow structure with one side open, and the open side of the second part 22 is placed over the open side of the first part 21 to form the housing 20 having the accommodation space 23. Of course, the first part 21 may have a hollow structure with one side open, and the second part 22 may have a plate-like structure, and the second part 22 is placed over the open side of the first part 21 to form the housing 20 having the accommodation space 23.

[0088] Referring to FIG. 3, FIG. 3 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, and a current collecting component 14, the case 11 has an opening 111, the electrode assembly 12 is housed within the case 11, the end cap 13 is placed over the opening 111, the end cap 13 is sealingly connected to the case 11, the current collecting component 14 is housed within the case 11, the current collecting component 14 is located on the side of the electrode assembly 12 facing the end cap 13, and the current collecting component 14 is configured to connect the case 11 and the electrode assembly 12 such that the electrode assembly 12 is electrically connected to the case 11.

[0089] Here, the end cap 13 can be placed over the opening 111 of the case 11 to form a sealed space 112 (not shown in FIG. 3) for accommodating the electrode assembly 12 and an electrolyte, which may be an electrolytic solution.

[0090] Since the current collecting part 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 by the current collecting part 14, the end cap 13 is placed over the opening 111 of the case 11, and the end cap 13 is sealed and connected to the case 11. With this structure, during the assembly process of the battery cell 10, the current collecting part 14 can be connected to the case 11 inside the case 11, and robustness can be ensured after the current collecting part 14 and the case 11 are connected. After the current collecting part 14 is connected to the electrode assembly 12 and the case 11, the end cap 13 is placed over the opening 111 of the case 11 and sealed and connected to the case 11, which further facilitates the electrical connection between the electrode assembly 12 and the case 11.

[0091] In a typical battery cell 10, the bottom wall of the case 11 is integrally welded to the tab, so that in the process of welding the bottom wall of the case 11 to the tab, the bottom wall of the case 11 is easily damaged, which causes leakage and affects the performance of the battery cell 10. In the embodiment of the present application, the electrode assembly 12 and the case 11 are electrically connected by the current collecting part 14, and the end cap 13 is sealed and connected to the case 11, so that the electrode assembly 12 is not directly connected to the end cap 13, and the battery cell 10 is less likely to leak from the end cap 13.

[0092] In some embodiments, the battery cell 10 may further include a sealing member 15, and the end cap 13 and the case 11 are sealed and connected by the sealing member 15 to ensure sealing performance between the end cap 13 and the case 11.

[0093] Optionally, the sealing member 15 is configured to insulate and separate the case 11 and the end cap 13, that is, the sealing member 15 not only performs a sealing function between the case 11 and the end cap 13, but also performs an insulating function, thereby ensuring the sealing performance between the end cap 13 and the case 11 and reducing the risk of charging the end cap 13.

[0094] The seal member 15 may be made of a material such as rubber, plastic, or the like, and the end cap 13 may be made of a metal material such as copper, iron, aluminum, steel, aluminum alloy, or the like.

[0095] In some other embodiments, the end cap 13 and the case 11 may be sealed by a tight fit, for example, an interference fit may be formed between the end cap 13 and the case 11 to achieve a sealed connection between the end cap 13 and the case 11. In this embodiment, the end cap 13 may be made of an insulating material to reduce the risk of electrostatic charging of the end cap 13.

[0096] In some embodiments, the battery cell 10 may further include a pressure relief mechanism 16, which is disposed in the end cap 13 and is configured to activate and release the internal pressure when the internal pressure or temperature of the battery cell 10 reaches a threshold value, so as to improve the safety of the battery cell 10.

[0097] The pressure relief mechanism 16 may be, for example, an explosion-proof valve, an explosion-proof plate, an air valve, a pressure relief valve, etc. In FIG. 3, the pressure relief mechanism 16 is exemplarily shown as an explosion-proof plate, which may be bonded to the end cap 13.

[0098] When the battery cell 10 experiences thermal runaway and emissions are discharged by the pressure relief mechanism 16, the end cap 13 may become charged, and if one of the end cap 13 and the case 11 becomes positively charged and the other becomes negatively charged, this may cause a short circuit in the battery cell 10. The seal member 15 insulates and separates the case 11 and the end cap 13, thereby effectively reducing the risk of a short circuit.

[0099] In the embodiments of the present application, the case 11 may have various shapes, for example, a cylinder, a rectangular parallelepiped, etc. The shape of the case 11 may be determined according to the specific shape of the electrode assembly 12. For example, if the electrode assembly 12 has a cylindrical structure, the case 11 may be selected to have a cylindrical structure, and if the electrode assembly 12 has a rectangular parallelepiped structure, the case 11 may be selected to have a rectangular parallelepiped structure.

[0100] Illustratively, in FIG. 3, the case 11 is a hollow cylindrical structure, and the electrode assembly 12 is a cylindrical structure.

[0101] The case 11 may be made of various materials, such as copper, iron, aluminum, steel, and aluminum alloy.

[0102] In some embodiments, the melting point of the case 11 may be higher than the melting point of the end caps 13. For example, the case 11 is made of a steel material and the end caps 13 are made of an aluminum material.

[0103] If the battery cell 10 experiences thermal runaway, the end cap 13 is more likely to melt because its melting point is lower than that of the case 11, reducing the possibility of the battery cell 10 exploding and impacting other battery cells 10, and reducing the risk of the entire battery 100 deforming and ultimately failing due to high voltage.

[0104] In some embodiments, referring to Fig. 4, Fig. 4 is a cross-sectional view of the battery cell 10 shown in Fig. 3, the case 11 may include a cylindrical body 113 and an output part 114, an opening 111 is provided at one end of the cylindrical body 113, the other end of the cylindrical body 113 is connected to the output part 114, the cylindrical body 113 is connected to the current collecting component 14, and the output part 114 is electrically connected to the electrode assembly 12. One of both the cylindrical body 113 and the output part 114 is a positive output pole of the battery cell 10, and the other is a negative output pole of the battery cell 10.

[0105] It can be understood that when the pressure relief mechanism 16 is installed in the end cap 13, the pressure relief mechanism 16 and the output part 114 are located on opposite sides of the case 11, and the pressure relief mechanism 16 does not occupy the space of the output part 114. This structure can ensure that the output part 114 and the busbar member have a large contact area, improving the overcurrent capacity. Taking the busbar member as an example, the output part 114 and the busbar member have a large welding area.

[0106] Illustratively, the barrel 113 is a cylindrical structure and the output portion 114 is a plate-like structure. The end cap 13 is used to cover the opening 111 at the end of the barrel 113 away from the output portion 114, and the end cap 13 may be a circular plate-like structure that fits the barrel 113.

[0107] Optionally, the cylinder 113 has a folded portion 1131 formed at an end away from the opening 111, and a portion of the cylinder 113 is recessed inward to form a first limit protrusion 1132, and the cylinder 113 forms a neck structure at the position of the first limit protrusion 1132. In the thickness direction Z of the end cap 13, the folded portion 1131 and the first limit protrusion 1132 are located on both sides of the output portion 114, respectively, and the folded portion 1131 and the first limit protrusion 1132 collectively limit the movement of the output portion 114 in the thickness direction of the end cap.

[0108] Illustratively, both the folded portion 1131 and the first limit protrusion 1132 have an annular structure.

[0109] It should be noted that in the battery cell 10, the output portion 114 may be a positive output terminal and the cylinder body 113 may be a negative output terminal, and the cylinder body 113 may be Positive The output pole is the output section 114. negativeThe positive output electrode and the negative output electrode are parts of the battery cell 10 that are connected to other members and are used to output the electrical energy of the battery cell 10. Take two battery cells 10 electrically connected by a bus bar member to realize a series connection of the two battery cells 10 as an example, and the positive output electrode of one battery cell 10 and the negative output electrode of the other battery cell 10 can both be welded to the bus bar member.

[0110] As can be understood, since there is an insulation state between the positive output terminal and the negative output terminal of the battery cell 10, both the cylinder 113 and the output portion 114 are insulated and connected. In some embodiments, the cylinder 113 and the output portion 114 may be insulated and separated by an insulating unit 17. The insulating unit 17 may be made of a material such as rubber, plastic, etc.

[0111] In some embodiments, the electrode assembly 12 may include a body 121 and a tab, the tab extending from the body 121. The body 121 may include a positive plate, a negative plate, and a separator. The body 121 may be a wound structure formed by winding a positive plate, a separator, and a negative plate. The body 121 may be a stacked structure formed by arranging a positive plate, a separator, and a negative plate in a stacked manner.

[0112] The positive plate includes a positive current collector and a layer of positive active material coated on opposing sides of the positive current collector. The negative plate includes a negative current collector and a layer of negative active material coated on opposing sides of the negative current collector. The body 121 is the portion of the electrode assembly 12 corresponding to the area of ​​the plate that is coated with the active material layer, and the tabs are the areas of the plate that are not coated with the active material layer.

[0113] The tab may be divided into a first tab 122 and a second tab 123, the first tab 122 may be connected to the current collecting part 14, realizing an electrical connection between the electrode assembly 12 and the cylindrical body 113 of the case 11, and the second tab 123 may be connected to the output part 114, realizing an electrical connection between the electrode assembly 12 and the output part 114.

[0114] Exemplarily, the first tab 122 may be a tubular structure, one end of the first tab 122 is connected to the body 121, and the other end of the first tab 122 is welded to the current collecting part 14. Such a structure can ensure the robustness of the connection between the first tab 122 and the current collecting part 14, and simplify the connection process between the first tab 122 and the current collecting part 14.

[0115] Exemplarily, the second tab 123 may be a tubular structure, one end of the second tab 123 is connected to the main body 121, and the other end of the second tab 123 is welded to the output portion 114. Such a structure can ensure the robustness of the connection between the second tab 123 and the output portion 114 and simplify the process of connecting the second tab 123 and the output portion 114.

[0116] One of the first tab 122 and the second tab 123 is a positive electrode tab, and the other is a negative electrode tab. The positive electrode tab is an area of ​​the positive electrode plate that is not coated with a positive electrode active material layer. The negative electrode tab is an area of ​​the negative electrode plate that is not coated with a negative electrode active material layer.

[0117] It should be noted that if the first tab 122 is a positive tab and the second tab 123 is a negative tab, then the barrel 113 is a positive output pole and the output 114 is a negative output pole. If the first tab 122 is a negative tab and the second plate is a positive tab, then the barrel 113 is a negative output pole and the output 114 is a positive output pole.

[0118] In the embodiment of the present application, the current collecting part 14 may be a metal conductor, such as copper, iron, aluminum, steel, aluminum alloy, etc. The current collecting part 14 may be connected to the case 11 in various ways. For example, the current collecting part 14 may be welded to the case 11, or for example, the current collecting part 14 and the case 11 may be bonded by a conductive adhesive.

[0119] In some embodiments, the current collecting piece 14 is welded to the case 11 and the melting point of the current collecting piece 14 is lower than the melting point of the case 11 .

[0120] When the current collecting part 14 is welded to the inside of the case 11, the melting point of the current collecting part 14 is lower than that of the case 11, so that the case 11 is less likely to be destroyed, and the risk of leakage from the case 11 is effectively reduced.

[0121] Taking the case 11 as an example made of steel and the current collecting part 14 as an example made of aluminum, the melting point of the case 11 is 1500°C, the melting point of the current collecting part 14 is 660°C, and during welding, the welding temperature can be selected to be between 660°C and 1500°C. For example, the welding temperature is 800°C, which does not reach the melting point of the case 11, and the case 11 is unlikely to be destroyed during the welding process.

[0122] Specifically, the melting point of current collecting part 14 is lower than the melting point of cylindrical body 113 of case 11 .

[0123] In some embodiments, referring to FIG. 5, FIG. 5 is a partially enlarged view of portion A of the battery cell 10 shown in FIG. 4, in which the current collecting part 14 is connected to the inner surface 115 of the case 11. With such a structure, the current collecting part 14 and the case 11 have a large contact area, which can effectively improve the robustness of the connection between the current collecting part 14 and the case 11 and improve the overcurrent capability.

[0124] The inner surface 115 of the case 11 is a surface formed by the generatrix moving along the circumferential direction of the opening 111 of the case 11, and the generatrix referred to here is a line disposed along the thickness direction Z of the end cap 13. Taking the case 11 as an example having a cylindrical structure, the inner surface 115 of the case 11 is the inner peripheral surface of the case 11.

[0125] Illustratively, the current collecting part 14 is welded to the inner surface 115 of the case 11 .

[0126] Optionally, the outer surface 131 of the end cap 13 and the inner surface 115 of the case 11 are disposed opposite to each other. At least a portion of the current collecting part 14 is located between the outer surface 131 of the end cap 13 and the inner surface 115 of the case 11, and the end cap 13 is configured to press a portion of the current collecting part 14 against the inner surface 115 of the case 11 so that the current collecting part 14 is in close contact with the case 11, thereby improving the robustness of the connection between the current collecting part 14 and the case 11.

[0127] It should be explained that the end cap 13 presses a portion of the current collecting part 14 against the inner surface 115 of the case 11, the end cap 13 may directly press a portion of the current collecting part 14 against the inner surface 115 of the case 11, i.e. the end cap 13 may directly abut against the current collecting part 14, or the end cap 13 may indirectly press a portion of the current collecting part 14 against the inner surface 115 of the case 11, i.e. the end cap 13 may indirectly abut against the current collecting part 14, for example, when the end cap 13 and the case 11 are sealed and connected by a sealing member 15, the end cap 13 indirectly abuts against the current collecting part 14 by the sealing member 15.

[0128] In some embodiments, the current collecting part 14 includes a first connecting portion 141 and a second connecting portion 142, and in the thickness direction Z of the end cap 13, at least a portion of the first connecting portion 141 is located between the end cap 13 and the electrode assembly 12, and the first connecting portion 141 is configured to be connected to the electrode assembly 12 so as to realize an electrical connection between the current collecting part 14 and the electrode assembly 12. The second connecting portion 142 is connected to the first connecting portion 141 and extends away from the electrode assembly 12 along the thickness direction Z of the end cap 13 from the first connecting portion 141, and the second connecting portion 142 is configured to be connected to the case 11. Such a current collecting part 14 has a simple structure, is easy to mold and manufacture, and can be easily connected to the electrode assembly 12 as well as the case 11.

[0129] Here, the first connection portion 141 is used to connect to the first tab 122 of the electrode assembly 12, for example, the first connection portion 141 is welded to the first tab 122. The second connection portion 142 may be connected to the inner surface 115 of the case 11, for example, the second connection portion 142 is welded to the inner surface 115 of the case 11.

[0130] For example, as shown in FIG. 5 , the end cap 13 uses a sealing member 15 to press the second connection portion 142 of the current collecting part 14 against the inner surface 115 of the case 11, thereby improving the robustness of the connection between the current collecting part 14 and the case 11.

[0131] Alternatively, the second connecting part 142 has an annular structure connected to the outer periphery of the first connecting part 141, and with this structure, the current collecting part 14 may be formed by a punching method, which is simple and easy to form. In addition, the annular second connecting part 142 and the case 11 have a large contact area, which is advantageous for improving the overcurrent capacity.

[0132] In some embodiments, the inner surface of the case 11 includes a stepped surface 116, and the current collecting part 14 abuts against the stepped surface 116 along a direction facing the electrode assembly 12, and the stepped surface 116 acts as a limiting force on the current collecting part 14, restricting the current collecting part 14 from moving along the direction facing the electrode assembly 12.

[0133] In the process of assembling the battery cell 10, the current collecting part 14 can be connected to the case 11 after the current collecting part 14 is abutted against the step surface 116, and attachment of the current collecting part 14 can be easily achieved.

[0134] Here, the stepped surface 116 is connected to the inner surface 115 of the case 11 , and the first connection portion 141 of the current collecting part 14 may abut against the stepped surface 116 along a direction facing the electrode assembly 12 .

[0135] 5, the current collecting part 14 may be connected to the inner surface 115 of the case 11. In other embodiments, the current collecting part 14 may not be connected to the inner surface 115 of the case 11, but may abut against and be connected to the stepped surface 116, for example, a first connecting portion 141 of the current collecting part 14 is welded to the stepped surface 116, and a second connecting portion 142 of the current collecting part is in contact with but not connected to the inner surface 115 of the case 11.

[0136] In some embodiments, referring again to FIG. 5 , the case 11 is provided with a limit portion 117 at one end of the opening 111, and the limit portion 117 is configured to restrict the end cap 13 from being detached from the case 11 along the direction away from the electrode assembly 12, i.e., the limit portion 117 exerts a restricting effect on the end cap 13, causing the case 11 to be detached along the direction away from the electrode assembly 12 by the restricting end cap 13.

[0137] As can be seen, the limit portion 117 is located at the end of the cylinder 113 of the case 11 away from the output portion 114 .

[0138] The limit portion 117 may have a folded structure in which a portion of the case 11 is folded inward. In other words, the limit portion 117 can be formed at the position of the opening 111 of the case 11 by folding the case 11, which simplifies molding.

[0139] In the process of assembling the battery cell 10, the current collecting parts 14 are accommodated in the case 11 and connected to the electrode assembly 12 and the case 11, and then the end caps 13 are placed over the openings 111 of the case 11, and finally the case 11 is folded back to form the limit portions 117 to limit the end caps 13.

[0140] The limit portion 117 may be provided in an annular configuration so that the limit portion 117 can have a better limiting ability against the end cap 13. Of course, the annular limit portion 117 makes it easier to achieve a seal with the end cap 13.

[0141] In some embodiments, in the thickness direction Z of the end cap 13, at least a portion of the end cap 13 is located between the limit portion 117 and the collecting part 14, and the limit portion 117 and the collecting part 14 jointly limit the movement of the end cap 13 in the thickness direction Z, so that the end cap 13 cannot easily move around within the case 11 along the thickness direction Z of the case 11.

[0142] For example, in FIG. 5, a portion of the end cap 13 is located between the limit portion 117 and the first connection portion 141 of the current collecting part 14 in the thickness direction Z of the end cap 13.

[0143] Both the limit portion 117 and the current collecting part 14 act to limit the movement of the end cap 13. The current collecting part 14 may directly or indirectly abut against the end cap 13, and the limit portion 117 may directly or indirectly abut against the end cap 13, so as to limit the movement of the end cap 13 in the thickness direction Z. For example, in FIG. 5, the end cap 13 abuts against the limit portion 117 by the seal member 15.

[0144] In some other embodiments, in the thickness direction Z of the end cap 13, at least a portion of the end cap 13 is located between the limit portion 117 and the step surface 116, and the limit portion 117 and the step surface 116 cooperate to limit the movement of the end cap 13 in the thickness direction Z, thereby preventing the end cap 13 from easily moving around within the case 11 along the thickness direction Z of the case 11.

[0145] Both the limit portion 117 and the step surface 116 act to limit the movement of the end cap 13. The limit portion 117 may be in direct or indirect contact with the end cap 13, and the step surface 116 may be in direct or indirect contact with the end cap 13, so as to limit the movement of the end cap 13 in the thickness direction Z.

[0146] 5 , in some embodiments, when the end cap 13 and the case 11 are sealed and connected by the sealing member 15, the sealing member 15 may be coated on the end cap 13 along the circumferential direction of the opening 111 of the case 11. Such a structure, on the one hand, improves the sealing performance of the sealing member 15 between 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. In the assembly process of the battery cell 10, the sealing member 15 can be coated on the end cap 13, and then the end cap 13 and the sealing member 15 can be attached to the case 11 as a unit.

[0147] In some embodiments, when a limit portion 117 is installed at one end of the opening 111 of the case 11, at least a portion of the sealing member 15 is located between the end cap 13 and the limit portion 117 in the thickness direction Z of the end cap 13 to realize a sealed connection between the end cap 13 and the case 11 and ensure good sealing between the end cap 13 and the case 11.

[0148] In some embodiments, the seal member 15 may include an enclosure 151 and a third connecting portion 152, where the third 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 in the thickness direction Z of the end cap 13, the third connecting portion 152 is located between the end cap 13 and the limit portion 117 to realize a sealed connection between the end cap 13 and the case 11.

[0149] Since at least a portion of the end cap 13 is located within the enclosure 151, the sealing member 15 covers the end cap 13 along the circumferential direction of the opening 111 of the case 11. Since the third connecting portion 152 is located between the end cap 13 and the limit portion 117, a sealed connection between the end cap 13 and the case 11 is realized, and even if the current collecting part 14 and the end cap 13 are not sealed, no leakage occurs between the end cap 13 and the case 11. The overall structure of the sealing member 15 is simple, and a good seal is realized between the end cap 13 and the case 11, and the sealing member 15 and the end cap 13 have very good unity.

[0150] When the seal member 15 has an insulating property, the enclosure 151 and the third connecting portion 152 of the seal member 15 can both perform an insulating function between the end cap 13 and the case 11 .

[0151] Illustratively, the end cap 13 presses the second connection portion 142 of the current collecting part 14 against the inner surface 115 of the case 11 by the enclosure 151 of the seal member 15. The third connection portion 152 and the limit portion 117 both have an annular structure, and the inner diameter of the third connection portion 152 is smaller than the inner diameter of the limit portion 117.

[0152] In some embodiments, referring to Fig. 6, Fig. 6 is a partial enlarged view of a battery cell 10 according to some other embodiments of the present application, in which the sealing member 15 may further include a fourth connection portion 153, and the enclosure 151, the third connection portion 152, and the fourth connection portion 153 are connected in sequence. The end cap 13 includes a main body portion 132 and an extension portion 133, the extension portion 133 extends from the main body portion 132 along a direction away from the electrode assembly 12, the enclosure 151 is located outside the extension portion 133, the fourth connection portion 153 is located inside the extension portion 133, and the third connection portion 152 is located between the extension portion 133 and the limit portion 117 in the thickness direction Z of the end cap 13. The limit portion 117 is provided with a bent portion 118, which is bent relative to the limit portion 117 in a direction approaching the electrode assembly 12, and the fourth connection portion 153 is located between the extension portion 133 and the bent portion 118. The limit portion 117 presses the third connection portion 152 against the extension portion 133, and the bent portion 118 presses the fourth connection portion 153 against the extension portion 133. This structure can further improve the sealing performance between the end cap 13 and the case 11.

[0153] Illustratively, the third connecting portion 152, the limit portion 117 and the fourth connecting portion 153 are all of annular structure.

[0154] In this embodiment, the case 11 may or may not have a step surface 116. For example, in FIG. 6, the case 11 does not have a step surface 116.

[0155] It should be explained that in the embodiment of the present application, the sealing member 15 is not limited to the above structure, and the sealing member 15 may have other structures. For example, the sealing member 15 includes only the enclosure 151, and the enclosure 151 has a structure with both ends open, and the enclosure 151 is covered on the outer periphery of the end cap 13, and the enclosure 151 abuts against the outer surface 131 of the end cap 13 and the inner surface 115 of the case 11, or the enclosure 151 abuts against the outer surface 131 of the end cap 13 and the second connecting portion 142 of the current collecting part 14, thereby realizing the sealing between the case 11 and the end cap 13. Also, for example, the sealing member 15 includes only the third connecting portion 152, and the third connecting portion 152 is located between the limit portion 117 and the end cap 13 in the thickness direction Z of the end cap 13, thereby realizing the sealing between the case 11 and the end cap 13.

[0156] It should be noted that in the embodiments of the present application, the step surface 116 of the case 11 can have various formation forms. For example, as shown in FIG. 5, a part of the case 11 approaching the opening 111 protrudes laterally, so that the inner diameter of the protruding part of the case 11 becomes larger than the inner diameter of the non-protruding part of the case 11, and further forms a step surface 116. Also, for example, refer to FIG. 7, which is a partial enlarged view of a battery cell 10 according to some further embodiments of the present application, in which a part of the case 11 is recessed inward to form a second limit protrusion 119, the case 11 forms a neck structure at the position of the second limit protrusion 119, the second limit protrusion 119 is used to limit the movement of the body 121 of the electrode assembly 12 in the direction approaching the end cap 13, and a step surface 116 is formed on the side of the second limit protrusion 119 away from the electrode assembly 12. Illustratively, the second limit protrusion 119 is an annular structure.

[0157] In some embodiments, referring to Fig. 8, Fig. 8 is a partial view of the battery cell 10 shown in Fig. 4, the battery cell 10 may further include an insulating member 18, in the thickness direction Z of the end cap 13, the insulating member 18 is located between the first tab 122 and the end cap 13, and the insulating member 18 covers the first tab 122 along the projection of the thickness direction Z of the end cap 13. The insulating member 18 serves to separate the end cap 13 and the first tab 122, and reduces the risk of the end cap 13 being charged.

[0158] The insulating member 18 covers the first tab 122 along the projection in the thickness direction Z of the end cap 13, i.e., the insulating member 18 covers an end face (an end face of the first tab 122 connected to the current collecting part 14) of the first tab 122 that is away from the main body 121 along the projection in the thickness direction Z of the end cap 13. Taking the first tab 122 as an example having a cylindrical structure, the insulating member 18 covers an annular end face of the first tab 122 that is away from the main body 121 along the projection in the thickness direction Z of the end cap 13.

[0159] The insulating member 18 may be made of a material such as rubber or plastic.

[0160] In some embodiments, in the thickness direction Z of the end cap 13, at least a portion of the insulating member 18 is located between the current collecting part 14 and the end cap 13 to insulate the current collecting part 14 from the end cap 13.

[0161] Illustratively, in the thickness direction Z of the end cap 13, a portion of the insulating member 18 is located between the first connection portion 141 of the current collecting part 14 and the end cap 13, thereby insulating and isolating the current collecting part 14 and the end cap 13. A first through hole 181 is provided in the insulating member 18, and a second through hole 143 is provided in the first connection portion 141, and the first through hole 181 and the second through hole 143 are both connected to the central hole 124 of the body 121 of the electrode assembly 12, and the first through hole 181 and the second through hole 143 are both disposed opposite the pressure relief mechanism 16, which facilitates the pressure relief mechanism 16 to release the pressure inside the battery cell 10 when the pressure or temperature inside the battery cell 10 reaches a threshold value.

[0162] As shown in Fig. 8, both the insulating member 18 and the sealing member 15 may be independent of each other, i.e., the insulating member 18 and the sealing member 15 are two separate members. In another embodiment, referring to Fig. 9, Fig. 9 is a partial view of a battery cell 10 according to another embodiment of the present application, both the insulating member 18 and the sealing member 15 may be an integrally molded structure, i.e., the insulating member 18 and the sealing member 15 are manufactured by integral molding. Exemplarily, in the thickness direction Z of the end cap 13, the insulating member 18 and the third connecting portion 152 are located at both ends of the enclosure 151, respectively, and the insulating member 18 and the third connecting portion 152 collectively restrict the end cap 13 from being detached from the sealing member 15.

[0163] An embodiment of the present application provides a method for manufacturing a battery cell 10. Referring to FIG. 10, FIG. 10 is a flow chart of a method for manufacturing a battery cell 10 according to some embodiments of the present application, the method includes: S100: Providing a case 11 having an opening 111; S200: Providing an electrode assembly 12; S300: Providing an end cap 13; S400: Providing a current collecting part 14; S500: Connecting the current collecting member 14 to the electrode assembly 12; S600: Housing the electrode assembly 12 and the current collecting member 14 in the case 11; S700: connecting the current collecting member 14 to the case 11 so that the electrode assembly 12 is electrically connected to the case 11; S800: The method includes placing the end cap 13 over the opening 111 of the case 11 and sealingly connecting the end cap 13 to the case 11 so that the current collecting part 14 is positioned on the side of the electrode assembly 12 facing the end cap 13.

[0164] In the above method, the order of steps S100, S200, S300 and S400 is not limited. For example, step S400 may be performed first, then step S300, then step S200, and finally step S100.

[0165] In some embodiments, step S700 may include welding the current collecting part 14 to the case 11 from inside the case 11, where the melting point of the current collecting part 14 is lower than the melting point of the case 11.

[0166] Since the melting point of the current collecting part 14 is lower than that of the case 11, by welding the current collecting part 14 to the case 11 from inside the case 11, the case 11 is less likely to be destroyed, and the risk of leakage from the case 11 is effectively reduced.

[0167] In some embodiments, referring to FIG. 11 , FIG. 11 is a flow chart of a method for manufacturing a battery cell 10 according to some other embodiments of the present application, after the end cap 13 is placed over the opening 111, the manufacturing method includes: S900: The method may further include performing a folding process on the case 11 so that the case 11 forms a limit portion 117 at the end where the opening 111 is located, so that the limit portion 117 restricts the end cap 13 from detaching the case 11 along a direction away from the electrode assembly 12.

[0168] The limit portion 117 is formed by folding back to restrict the end cap 13 from being detached from the case 11 in the direction away from the electrode assembly 12, which is simple to implement and can effectively reduce manufacturing costs.

[0169] It should be noted that the relevant structures of the battery cell 10 manufactured by the manufacturing methods according to the above embodiments may be referred to the battery cell 10 according to the above embodiments, and will not be further described here.

[0170] In addition, an embodiment of the present application further provides a manufacturing equipment 2000 for the battery cell 10. Referring to FIG. 12, FIG. 12 is a schematic block diagram of a manufacturing equipment 2000 for the battery cell 10 according to some embodiments of the present application, where the manufacturing equipment 2000 includes a first providing apparatus 1100, a second providing apparatus 1200, a third providing apparatus 1300, a fourth providing apparatus 1400 and an assembly apparatus 1500.

[0171] The first providing device 1100 is used to provide a case 11 having an opening 111. The second providing device 1200 is used to provide an electrode assembly 12. The third providing device 1300 is used to provide an end cap 13. The fourth providing device 1400 is used to provide a current collecting part 14. The assembling device 1500 is used to connect the current collecting part 14 to the electrode assembly 12, accommodate the electrode assembly 12 and the current collecting part 14 in the case 11, connect the current collecting part 14 to the case 11 so that the electrode assembly 12 is electrically connected to the case 11, cover the end cap 13 over the opening 111, and seal-connect the end cap 13 to the case 11, so that the current collecting part 14 is positioned on the side of the electrode assembly 12 facing the end cap 13.

[0172] It should be noted that the relevant structures of the battery cell 10 manufactured by the manufacturing equipment 2000 according to the above embodiments may be referred to the battery cell 10 according to the above embodiments, and will not be further described here.

[0173] It should be mentioned that, unless there is a conflict, the embodiments and features in the embodiments in the present application can be combined with each other.

[0174] The above examples are only intended to explain the technical solution of the present application, and are not intended to limit the present application, and those skilled in the art may make various modifications and variations to the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application. [Explanation of symbols]

[0175] 10 Battery Cells 11 Cases 12 Electrode Assembly 13 End cap 14 Current collector 15 Sealing material 16 Pressure relief mechanism 17 Isolation unit 18 Insulating materials 20. Cabinet 21 First Part 22 Second Part 23 Containment Space 100 batteries 111 Aperture 112 Sealing space 113 Cylinder 114 Output section 115 Inner surface 116 Step surface 117 Limit Section 118 Refraction 119 Second limit protrusion 121 Main unit 122 First Tab 123 Second Tab 124 Center hole 131 External surface 132 Main body 133 Extension 141 First Connection 142 Second Connection 143 Second through hole 151 Enclosure 152 Third Connection 153 Fourth Connection 181 First Through Hole 200 Controller 300 Motor 1000 vehicles 1100 First providing device 1131 Folding part 1132 First limit protrusion 1200 Secondary provider 1300 Third provision device 1400 The fourth provision device 1500 Assembly Equipment 2000 Manufacturing equipment

Claims

1. A battery cell, a case having an opening; an electrode assembly housed within the case; an end cap that covers the opening and is sealingly connected to the case; a current collecting part that is accommodated in the case and is located on a side of the electrode assembly facing the end cap, the current collecting part being configured to connect the case and the electrode assembly such that the electrode assembly is electrically connected to the case; A battery cell, wherein the current collecting part is welded to the case, and the melting point of the current collecting part is lower than the melting point of the case.

2. The battery cell according to claim 1 , wherein the current collecting component is connected to an inner surface of the case.

3. The outer surface of the end cap and the inner surface of the case are disposed opposite each other, 3. The battery cell of claim 2, wherein at least a portion of the current collecting component is located between an outer surface of the end cap and an inner surface of the case, and the end cap is configured to press a portion of the current collecting component against the inner surface of the case.

4. the current collecting component includes a first connection portion and a second connection portion, In a thickness direction of the end cap, at least a portion of the first connection portion is located between the end cap and the electrode assembly, and the first connection portion is configured to be connected to the electrode assembly; 4. The battery cell according to claim 1, wherein the second connection portion is connected to the first connection portion and extends from the first connection portion along a thickness direction of the end cap away from the electrode assembly, and the second connection portion is configured to be connected to the case.

5. The battery cell according to claim 4 , wherein the second connection portion has an annular structure connected to an outer edge of the first connection portion.

6. The case has a limit portion provided at one end of the opening, The battery cell according to claim 1 , wherein the limit portion is configured to restrict the end cap from being detached from the case along a direction away from the electrode assembly.

7. 7. The battery cell of claim 6, wherein in a thickness direction of the end cap, at least a portion of the end cap is located between the limit portion and the current collecting component, and the limit portion and the current collecting component jointly limit movement of the end cap in the thickness direction of the end cap.

8. the inner surface of the case includes a stepped surface, 7. The battery cell of claim 6, wherein in a thickness direction of the end cap, at least a portion of the end cap is located between the limit portion and the step surface, and the limit portion and the step surface collectively limit movement of the end cap in the thickness direction of the end cap.

9. The battery cell according to claim 6 , wherein the limit portion has an annular structure.

10. The battery cell according to claim 6 , wherein the limit portion has a folded structure in which a portion of the case is folded inward.

11. the inner surface of the case includes a stepped surface, The battery cell according to claim 1 , wherein the current collecting part abuts against the stepped surface along a direction facing the electrode assembly.

12. The battery cell further includes a sealing member, The battery cell according to claim 1 , wherein the end cap and the case are sealed and connected by the sealing member.

13. The battery cell according to claim 12 , wherein the sealing member is configured to electrically insulate the case and the end cap.

14. The battery cell according to claim 12 or 13, wherein the sealing member is configured to be covered by the end cap along a circumferential direction of the opening.

15. 15. The battery cell according to claim 12, wherein the case has a limit portion at one end of the opening, and in the thickness direction of the end cap, at least a portion of the sealing member is located between the end cap and the limit portion to achieve a sealed connection between the end cap and the case.

16. the seal member includes an enclosure and a third connection portion, the third connection portion being connected to the enclosure; 16. The battery cell of claim 15, wherein at least a portion of the end cap is located within the enclosure, and in a thickness direction of the end cap, the third connection portion is located between the end cap and a limit portion to realize a sealed connection between the end cap and a case.

17. the electrode assembly includes a first tab, the first tab configured to be connected to the current collecting piece; 17. The battery cell of claim 1, further comprising an insulating member, the insulating member being located between the first tab and the end cap in a thickness direction of the end cap, and the insulating member covering the first tab along a projection in the thickness direction of the end cap.

18. 18. The battery cell of claim 1, wherein the electrode assembly includes a body and a first tab, the first tab having a cylindrical structure, one end of the first tab is connected to the body, and the other end of the first tab is welded to the current collecting part.

19. The battery cell further includes a pressure relief mechanism.

19. The battery cell of claim 1 , wherein the pressure relief mechanism is disposed in the end cap, and the pressure relief mechanism is configured to be activated to release the internal pressure when a pressure or temperature inside the battery cell reaches a threshold value.

20. A battery comprising a plurality of battery cells according to any one of claims 1 to 19.

21. 20. A power consuming device comprising a battery cell according to any one of claims 1 to 19.

22. 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 collecting component; connecting a current collecting piece to the electrode assembly; housing the electrode assembly and the current collecting piece in the case; connecting the current collecting piece to the case such that the electrode assembly is electrically connected to the case; and placing the end cap over the opening and sealingly connecting the end cap to the case, so that the current collecting part is located on a side of the electrode assembly facing the end cap; welding the current collecting part to the case from inside the case; A method for manufacturing a battery cell, wherein the melting point of the current collecting part is lower than the melting point of the case.

23. The manufacturing method includes:

23. The manufacturing method of claim 22, further comprising: performing a folding process on the case after the end cap is placed over the opening, so that the case forms a limit portion at an end where the opening is located, and the limit portion restricts the end cap from being detached from the case along a direction away from the electrode assembly.

24. A battery cell manufacturing device comprising: 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 presenting device for presenting a current collecting piece; an assembly device for connecting a current collecting part to the electrode assembly, housing the electrode assembly and the current collecting part in the case, connecting the current collecting part to the case so that the electrode assembly is electrically connected to the case, placing the end cap over the opening, and sealingly connecting the end cap to the case, so that the current collecting part is located on a side of the electrode assembly facing the end cap; The current collecting part is welded to the case, and the melting point of the current collecting part is lower than the melting point of the case.

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