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

Abstract

The embodiments of the present application provide a battery cell, a battery, an electrical device, and a manufacturing method and equipment for a battery cell, which belong to the field of battery technology. Among them, the battery cell includes an electrode assembly, a shell and an end cover. The electrode assembly has a first tab. The shell has an opening, and the shell is used to accommodate the electrode assembly. The end cover includes a cover body and a first protrusion, the cover body is used to connect with the shell and cover the opening, the first protrusion protrudes from the inner surface of the cover body in the direction facing the electrode assembly, and abuts against the first tab. An injection hole is provided on the end cover, and the injection hole is located on the inner side of the outer peripheral surface of the first protrusion. The first protrusion is provided with a guide channel, which is connected to the injection hole and passes through the outer peripheral surface. The guide channel is used to supply at least part of the electrolyte to flow outside the outer peripheral surface. In the process of injecting electrolyte into the battery cell through the injection hole, the electrolyte can flow laterally to the outside of the outer peripheral surface of the first protrusion through the guide channel, which can effectively improve the injection efficiency.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a battery, an electrical device, and a method and equipment for manufacturing the battery cell. Background Art

[0002] Batteries are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes and power tools, etc.

[0003] A battery cell generally includes a shell and an electrode assembly. The shell is used to accommodate the electrode assembly and electrolyte. The electrode assembly generally includes a positive electrode sheet and a negative electrode sheet. Electric energy is generated by the movement of metal ions (such as lithium ions) between the positive electrode sheet and the negative electrode sheet.

[0004] For a general battery cell, it is difficult to inject electrolyte into the battery cell through the injection hole, and the injection efficiency is low. Summary of the Invention

[0005] The embodiments of the present application provide a battery cell, a battery, an electrical device, and a method and device for manufacturing the battery cell, which can effectively improve the liquid injection efficiency.

[0006] In the first aspect, an embodiment of the present application provides a battery cell, comprising: an electrode assembly having a first pole ear; a shell having an opening, the shell being used to accommodate the electrode assembly; and an end cover, comprising a cover body and a first protrusion, the cover body being used to connect to the shell and cover the opening, the first protrusion protruding from the inner surface of the cover body in a direction facing the electrode assembly and abutting against the first pole ear; an injection hole is provided on the end cover, the injection hole is used to allow electrolyte to enter the interior of the battery cell from the outside of the battery cell, and the injection hole is located on the inner side of the outer peripheral surface of the first protrusion; wherein the first protrusion is provided with a guide channel, the guide channel is connected to the injection hole and passes through the outer peripheral surface, and the guide channel is used to allow at least part of the electrolyte to flow to the outside of the outer peripheral surface.

[0007] In the above technical solution, since a guide channel is provided on the first convex portion, the guide channel is connected to the injection hole and passes through the outer peripheral surface of the first convex portion. During the process of injecting electrolyte into the battery cell through the injection hole, the electrolyte can flow laterally through the guide channel to the outside of the outer peripheral surface of the first convex portion, thereby allowing the electrolyte to flow quickly to the periphery of the electrode assembly, improving the smoothness of the electrolyte flow, effectively improving the injection efficiency, and allowing the electrolyte to fully infiltrate the electrode assembly.

[0008] In some embodiments, abutment surface is formed on one end of the first protrusion facing away from the cover body, and the abutment surface is used to abut against the first electrode tab; the end cover is provided with a first recessed portion that is recessed from the abutment surface in a direction away from the electrode assembly, and the injection hole is connected to the guide channel through the first recessed portion.

[0009] In the above technical solution, a first recess is provided on the end cover, which is recessed from the abutting surface of the first convex portion in the direction away from the electrode assembly, and the injection hole and the guide channel are connected through the first recess. This structure allows the electrolyte to enter the first recess through the injection hole. After that, a part of the electrolyte can directly enter the interior of the electrode assembly through the first recess to infiltrate the electrode sheet, and a part of the electrolyte can enter the guide channel through the first recess and finally flow to the outside of the outer peripheral surface of the first convex portion, thereby improving the wetting effect of the electrolyte on the electrode assembly and improving the injection efficiency.

[0010] In some embodiments, two ends of the guide channel respectively pass through the outer circumferential surface and the inner circumferential surface of the first recess.

[0011] In the above technical solution, the two ends of the guide channel respectively penetrate the outer peripheral surface and the inner peripheral surface of the first recess, which is conducive to the electrolyte entering the guide channel from the first recess and facilitating the electrolyte to flow laterally to the outside of the outer peripheral surface of the first protrusion.

[0012] In some embodiments, the end cover has a liquid outlet surface, one end of the liquid injection hole passes through the liquid outlet surface, and the liquid outlet surface is located in the first recess; in the thickness direction of the end cover, the liquid outlet surface is farther away from the electrode assembly than the abutment surface.

[0013] In the above technical solution, the liquid outlet surface is farther away from the electrode assembly than the abutment surface in the thickness direction of the end cover, so that there is a distance between the liquid outlet surface and the electrode assembly, which facilitates the electrolyte to enter the first recess from the injection hole, is beneficial for the electrolyte to immerse into the electrode assembly, and is beneficial for the lateral flow of the electrolyte.

[0014] In some embodiments, in the thickness direction of the end cover, the guide channel as a whole is closer to the electrode assembly than the liquid outlet surface.

[0015] In the above technical solution, the guide channel as a whole is closer to the electrode assembly than the liquid outlet surface in the thickness direction of the end cover, so that there is a larger distance between the liquid outlet surface and the electrode assembly, and the electrolyte can more easily enter the guide channel.

[0016] In some embodiments, the end cap further includes: a second protrusion, located in the first recess, and protruding from the bottom surface of the first recess in a direction facing the electrode assembly, and the liquid outlet surface is formed at one end of the second protrusion facing the electrode assembly.

[0017] In the above technical solution, the second convex portion located inside the first concave portion can reinforce the position where the injection hole is provided in the end cover, thereby improving the strength of the position where the injection hole is provided in the end cover.

[0018] In some embodiments, the guide channel is a guide groove provided at an end of the first protrusion facing away from the cover body.

[0019] In the above technical solution, the flow channel is a groove disposed at the end of the first protrusion facing away from the cover body, which facilitates the formation of the flow channel. Furthermore, because the side of the groove facing the electrode assembly is open, a portion of the electrolyte flowing through the flow channel can flow directly into the interior of the electrode assembly, improving the wetting effect on the electrode assembly.

[0020] In some embodiments, the first protrusion is provided with a plurality of the guide channels arranged circumferentially and spaced apart with the liquid injection hole as the center.

[0021] In the above technical solution, the first convex portion is provided with a plurality of guide channels arranged circumferentially with the injection hole as the center. The electrolyte can flow in a plurality of different directions through the plurality of guide channels, further improving the injection efficiency.

[0022] In some embodiments, the guide channel extends radially along the injection hole.

[0023] In the above technical solution, the guide channel extends radially along the injection hole, which facilitates the electrolyte to enter the guide channel and improves the injection efficiency.

[0024] In some embodiments, the injection hole is coaxially arranged with the first protrusion.

[0025] In some embodiments, the electrode assembly has a central hole, and in the thickness direction of the end cover, the central hole is arranged opposite to the injection hole.

[0026] In the above technical solution, the center hole and the injection hole are arranged opposite to each other in the thickness direction of the end cover. During the process of injecting electrolyte into the battery cell through the injection hole, the electrolyte entering the injection hole can quickly enter the center hole to infiltrate the electrode sheets in the electrode assembly.

[0027] In a second aspect, an embodiment of the present application provides a battery, comprising: a battery cell provided in any one embodiment of the first aspect; and a box for accommodating the battery cell.

[0028] In a third aspect, an embodiment of the present application provides an electrical device, comprising a battery provided in any one embodiment of the second aspect.

[0029] 18. The battery pack of claim 17, wherein the cover has an indentation on its side that is adapted to engage with the first tab of the battery pack and an indentation on its side that is adapted to engage with the first tab of the battery pack.

[0030] In a fifth aspect, an embodiment of the present application further provides a manufacturing device for a battery cell, the manufacturing device comprising: a first providing device for providing an electrode assembly, the electrode assembly having a first electrode tab; a second providing device for providing a shell having an opening; a third providing device for providing an end cap; an assembling device for accommodating the electrode assembly in the shell; and further for covering the end cap with the opening; wherein the end cap comprises a cover body and a first protrusion, the cover body being configured to be connected to the shell and covering the opening, the first protrusion protruding from the inner surface of the cover body in a direction facing the electrode assembly, the first protrusion being configured to abut against the first electrode tab; a liquid injection hole being provided on the end cap, the liquid injection hole being configured to allow electrolyte to enter the interior of the battery cell from the outside of the battery cell, the liquid injection hole being located on the inner side of the outer peripheral surface of the first protrusion; a flow guide channel being provided on the first protrusion, the flow guide channel being connected to the liquid injection hole and penetrating the outer peripheral surface, the flow guide channel being configured to allow electrolyte entering the liquid injection hole to flow to the outside of the outer peripheral surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0033] Figure 2 A schematic diagram of the structure of a battery provided in some embodiments of the present application;

[0034] Figure 3 An exploded view of a battery cell provided in some embodiments of the present application;

[0035] Figure 4 for Figure 3 A cross-sectional view of a battery cell is shown;

[0036] Figure 5 for Figure 4 A partial view of a battery cell is shown;

[0037] Figure 6 for Figure 5 The structural diagram of the end cover shown;

[0038] Figure 7 for Figure 4 A partial enlarged view of the battery cell A shown;

[0039] Figure 8 A flowchart of a method for manufacturing a battery cell provided in some embodiments of the present application;

[0040] Figure 9 A schematic block diagram of a battery cell manufacturing device provided in some embodiments of the present application.

[0041] Icons: 100 - battery; 10 - housing; 11 - first part; 12 - second part; 13 - storage space; 20 - battery cell; 21 - electrode assembly; 211 - first tab; 212 - main body; 213 - second tab; 214 - center hole; 22 - housing; 221 - end wall; 222 - peripheral wall; 223 - first limiting portion; 224 - second limiting portion; 225 - roller groove; 23 - end cover; 231 - cover body; 232 - first convex portion; 2321 - abutment surface; 233 - injection hole; 234 - diversion channel ;235-first concave portion;236-liquid outlet surface;237-second convex portion;238-third convex portion;239-second concave portion;24-sealing member;25-insulating member;251-first connecting portion;252-second connecting portion;253-third connecting portion;254-fourth connecting portion;200-controller;300-motor;1000-vehicle;2000-manufacturing equipment;2100-first providing device;2200-second providing device;2300-third providing device;2400-assembling device;Z-thickness direction. DETAILED DESCRIPTION

[0042] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0043] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0044] References to "embodiments" in this application mean 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 appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0045] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0046] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0047] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0048] The term "plurality" used in this application refers to two or more (including two).

[0049] In this application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application do not limit this. Battery cells may be cylindrical, flat, rectangular, or other shapes, etc., and the embodiments of this application do not limit this. Battery cells are generally divided into three types based on the packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this.

[0050] The battery referred to in the embodiments of this 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 this application may include a battery module or a battery pack. A battery generally includes a casing that encloses one or more battery cells. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0051] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell primarily operates by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive electrode collector. The uncoated positive electrode collector protrudes from the coated positive electrode collector, and the uncoated positive electrode collector serves as the positive electrode tab. For lithium-ion batteries, for example, the positive electrode current collector can be made of aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative electrode collector. The uncoated negative electrode collector protrudes from the coated negative electrode collector, and the uncoated negative electrode collector serves as the negative electrode tab. The negative electrode current collector can be made of copper, and the negative electrode active material can be carbon or silicon, among others. To ensure that high currents can pass without fusing, multiple positive electrode tabs are stacked together, and multiple negative electrode tabs are stacked together. The separator can be made of materials such as PP (polypropylene) or PE (polyethylene). Furthermore, the electrode assembly can be a wound or laminated structure, but the embodiments of the present application are not limited thereto.

[0052] For a general battery cell, it is difficult to inject electrolyte into the battery cell through the injection hole, and the injection efficiency is low.

[0053] The inventors discovered that in a battery cell, when the end cap is electrically connected to the tab of the electrode assembly, the inner surface of the end cap abuts against the tab. During the process of injecting electrolyte into the battery cell through the injection hole on the end cap, it is difficult for the electrolyte to flow laterally between the inner surface of the end cap and the tab, resulting in low injection efficiency.

[0054] In view of this, an embodiment of the present application provides a technical solution, in which the end cover of the battery cell includes a cover body and a first protrusion, the first protrusion protrudes from the inner surface of the cover body in a direction facing the electrode assembly, and abuts against the first pole ear, and the first protrusion is provided with a guide channel, which is connected to the injection hole on the end cover and passes through the outer peripheral surface of the first protrusion, so that the electrolyte can flow laterally through the guide channel to the outside of the outer peripheral surface of the first protrusion, thereby improving the injection efficiency.

[0055] The technical solutions described in the embodiments of the present application are applicable to battery cells, batteries, and electrical equipment using batteries.

[0056] Electrical equipment can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and electric tools, etc. Vehicles can be fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical equipment.

[0057] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0058] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of the present application. A battery 100 is disposed inside the vehicle 1000. The battery 100 can be disposed at the bottom, head, or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can serve as an operating power source for the vehicle 1000.

[0059] The vehicle 1000 may further include a controller 200 and a motor 300 . The controller 200 is used to control the battery 100 to supply power to the motor 300 , for example, to meet the power requirements of the vehicle 1000 during startup, navigation, and driving.

[0060] In some embodiments of the present application, the battery 100 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0061] In some embodiments, please refer to Figure 2 , Figure 2 This is a structural diagram of a battery 100 provided in some embodiments of the present application. The battery 100 includes a box body 10 and a battery cell 20 . The box body 10 is used to accommodate the battery cell 20 .

[0062] The box body 10 may include a first portion 11 and a second portion 12, which cover each other to define a storage space 13 for accommodating the battery cell 20. The first portion 11 and the second portion 12 may be in various shapes, such as a rectangular parallelepiped, a cylinder, etc. The first portion 11 may be a hollow structure with one side open, and the second portion 12 may also be a hollow structure with one side open. The open side of the second portion 12 covers the open side of the first portion 11, thereby forming a box body 10 with a storage cavity. Figure 2 As shown, the first part 11 may be a hollow structure with one side open, and the second part 12 may be a plate-like structure, and the second part 12 may cover the open side of the first part 11, thereby forming a box body 10 with a receiving cavity. Figure 2 In the figure, the first part 11 and the second part 12 are both rectangular parallelepiped structures.

[0063] The first portion 11 and the second portion 12 can be sealed by a sealing element, which can be a sealing ring, sealant, etc.

[0064] In the battery 100, there can be one or more battery cells 20. If there are multiple battery cells 20, the multiple battery cells 20 can be connected in series, parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. Multiple battery cells 20 can be connected in series, parallel, or in a hybrid connection to form a battery module, which is then connected in series, parallel, or in a hybrid connection to form a whole and housed within the housing 10. Alternatively, all battery cells 20 can be directly connected in series, parallel, or in a hybrid connection, and then the whole battery module can be housed within the housing 10.

[0065] In some embodiments, the battery 100 may further include a busbar component, and the multiple battery cells 20 may be electrically connected via the busbar component to achieve series connection, parallel connection, or mixed connection of the multiple battery cells 20 .

[0066] The busbar component may be a metal conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0067] Please refer to Figure 3 and Figure 4 , Figure 3 An exploded view of a battery cell 20 provided in some embodiments of the present application, Figure 4 for Figure 3 The cross-sectional view of the battery cell 20 shown in FIG. 2 includes an electrode assembly 21 , a shell 22 and an end cover 23 . The electrode assembly 21 has a first electrode tab 211 . The shell 22 has an opening. The shell 22 is used to accommodate the electrode assembly 21 . The end cover 23 is used to connect to and cover the opening of the shell 22 .

[0068] The end cap 23 includes a cover body 231 and a first protrusion 232. The cover body 231 is used to connect to the housing 22 and cover the opening. The first protrusion 232 protrudes from the inner surface of the cover body 231 in a direction facing the electrode assembly 21 and abuts against the first electrode tab 211. The end cap 23 is provided with an injection hole 233, which is used to allow electrolyte to enter the battery cell 20 from the outside of the battery cell 20. The injection hole 233 is located on the inner side of the outer peripheral surface of the first protrusion 232. The first protrusion 232 is provided with a guide channel 234, which is connected to the injection hole 233 and extends through the outer peripheral surface of the first protrusion 232. The guide channel 234 is used to allow at least part of the electrolyte to flow outside the outer peripheral surface of the first protrusion 232.

[0069] Because the first protrusion 232 is provided with a flow channel 234, which is connected to the injection hole 233 and extends through the outer circumference of the first protrusion 232, during the process of injecting electrolyte into the battery cell 20 through the injection hole 233, the electrolyte can flow laterally through the flow channel 234 to the outside of the outer circumference of the first protrusion 232, thereby allowing the electrolyte to quickly flow to the periphery of the electrode assembly 21, improving the smoothness of the electrolyte flow, effectively improving the injection efficiency, and ensuring that the electrolyte fully infiltrates the electrode assembly 21. For the battery cell 20 with the above structure, injection can be achieved without excessive injection pressure, which can effectively reduce the risk of damage to the separator in the electrode assembly 21 due to excessive injection pressure, resulting in direct contact and short circuit between the positive and negative electrode sheets.

[0070] The first protrusion 232 of the end cap 23 abuts against the first tab 211, thereby achieving electrical connection between the end cap 23 and the first tab 211. To ensure good contact between the first tab 211 and the end cap 23, the first protrusion 232 of the end cap 23 can be fixed to the first tab 211, for example, by welding the first protrusion 232 and the first tab 211 together.

[0071] It should be noted that the injection hole 233 is located on the inner side of the outer circumference of the first convex portion 232, that is, the outer circumference of the first convex portion 232 is located on the periphery of the injection hole 233. The injection hole 233 can be located at the center of the first convex portion 232, or the injection hole 233 can be offset from the center of the first convex portion 232. Exemplarily, the injection hole 233 is coaxial with the first convex portion 232, that is, the axis of the injection hole 233 coincides with the axis of the outer circumference of the first convex portion 232, so that the injection hole 233 is located at the center of the first convex portion 232.

[0072] In some embodiments, the electrode assembly 21 may further include a main body 212 and a second tab 213. The first tab 211 and the second tab 213 both protrude from the main body 212. The first tab 211 and the second tab 213 have opposite polarities. If the first tab 211 is a positive tab, the second tab 213 is a negative tab; if the first tab 211 is a negative tab, the second tab 213 is a positive tab. The first tab 211 is electrically connected to the end cap 23, and the second tab 213 is electrically connected to the housing 22.

[0073] Illustratively, the first electrode tab 211 and the second electrode tab 213 respectively protrude from opposite ends of the main body 212 in the thickness direction Z of the end cover 23 .

[0074] The main body 212 may include a positive electrode sheet, a negative electrode sheet, and a separator. The main body 212 may be a wound structure formed by winding the positive electrode sheet, separator, and negative electrode sheet. The main body 212 may also be a stacked structure formed by stacking the positive electrode sheet, separator, and negative electrode sheet.

[0075] The positive electrode sheet includes a positive current collector and a positive active material layer coated on opposite sides of the positive current collector. The negative electrode sheet includes a negative current collector and a negative active material layer coated on opposite sides of the negative current collector. The main body 212 can be the portion of the electrode assembly 21 corresponding to the area of the electrode sheet coated with the active material layer, and the tab can be the portion of the electrode assembly 21 corresponding to the area of the electrode sheet not coated with the active material layer. It is understood that the positive electrode tab can be the area on the positive electrode sheet not coated with the positive active material layer, and the negative electrode tab can be the area on the negative electrode sheet not coated with the negative active material layer.

[0076] In the embodiment of the present application, the shell 22 is used to accommodate the electrode assembly 21. The shell 22 can be in various shapes, such as a cylinder, a cuboid, etc. The shape of the shell 22 can be determined according to the specific shape of the electrode assembly 21. For example, if the electrode assembly 21 is a cylindrical structure, the shell 22 can be a cylindrical structure; if the electrode assembly 21 is a cuboid structure, the shell 22 can be a cuboid structure. For example, in Figure 3 and Figure 4 In the embodiment, the shell 22 is a hollow cylindrical structure.

[0077] The housing 22 may be made of metal, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0078] In some embodiments, the shell 22 may include an end wall 221 and a peripheral wall 222 surrounding the edge of the end wall 221, the end wall 221 is located at one end of the peripheral wall 222, and an opening is formed at the other end of the peripheral wall 222, and the end cover 23 is used to be connected to the peripheral wall 222 and cover the opening to form a sealed space for accommodating the electrode assembly 21 and the electrolyte.

[0079] Exemplarily, the second electrode tab 213 is welded to the end wall 221 of the housing 22 to achieve electrical connection between the second electrode tab 213 and the housing 22 .

[0080] It should be noted that the end wall 221 and the peripheral wall 222 can be an integrally formed structure or a split structure. If the end wall 221 and the peripheral wall 222 are split structures, the housing 22 is formed by assembling the two together.

[0081] In some embodiments, the peripheral wall 222 of the housing 22 is formed with a first limiting portion 223 and a second limiting portion 224. The first limiting portion 223 is located on the side of the cover body 231 facing the electrode assembly 21, and the second limiting portion 224 is located on the side of the cover body 231 facing away from the electrode assembly 21. In the thickness direction Z of the end cap 23, the first limiting portion 223 is used to limit the movement of the cover body 231 relative to the housing 22 in the direction facing the electrode assembly 21, thereby reducing the risk of damage to the electrode assembly 21 caused by the end cap 23 being squeezed by force. The second limiting portion 224 is used to limit the movement of the cover body 231 relative to the housing 22 in the direction away from the electrode assembly 21, thereby preventing the end cap 23 from separating from the housing 22. In other words, the first limiting portion 223 and the second limiting portion 224 cooperate to limit the movement of the cover body 231 relative to the housing 22 along the thickness direction Z of the end cap 23.

[0082] The first limiting portion 223 and the second limiting portion 224 may both be annular structures.

[0083] Exemplarily, a roller groove 225 is provided on the peripheral wall 222 of the shell 22, which is recessed inwardly toward the outer peripheral surface of the peripheral wall 222, and a first limiting portion 223 is formed on the inner peripheral surface of the peripheral wall 222 at a position corresponding to the roller groove 225, so that the shell 22 has a necking structure at the position where the first limiting portion 223 is formed.

[0084] Illustratively, the second limiting portion 224 is a flange structure formed by partially folding the peripheral wall 222 of the shell 22 inward and forming the flange structure at the opening position.

[0085] During the assembly of the battery cell 20, the electrode assembly 21 can be first accommodated in the shell 22, and then the end cover 23 can be covered on the end of the peripheral wall 222 away from the end wall 221. The end cover 23 cannot move toward the interior of the shell 22 due to the restriction of the first limiting portion 223. Finally, the peripheral wall 222 of the shell 22 is partially folded inward to form a second limiting portion 224 to fix the end cover 23.

[0086] In the embodiment of the present application, the guide channel 234 is connected to the injection hole 233. The guide channel 234 can be directly connected to the injection hole 233. For example, one end of the guide channel 234 directly passes through the hole wall of the injection hole 233. Of course, the guide channel 234 can also be indirectly connected to the injection hole 233.

[0087] In some embodiments, please refer to Figure 5 , Figure 5 for Figure 4 In the partial view of the battery cell 20 shown, the flow channel 234 is indirectly connected to the injection hole 233. Specifically, an abutment surface 2321 is formed on the end of the first protrusion 232 facing away from the cover body 231. The abutment surface 2321 is used to abut against the first electrode tab 211. The end cap 23 is provided with a first recess 235 that is recessed from the abutment surface 2321 in a direction away from the electrode assembly 21. The injection hole 233 and the flow channel 234 are connected through the first recess 235. This structure allows the electrolyte to enter the first recess 235 through the injection hole 233. A portion of the electrolyte can directly enter the interior of the electrode assembly 21 through the first recess 235 to infiltrate the electrode sheet, while a portion of the electrolyte can enter the flow channel 234 through the first recess 235 and ultimately flow outside the outer peripheral surface of the first protrusion 232. This improves the wetting effect of the electrolyte on the electrode assembly 21 and improves the injection efficiency.

[0088] Illustratively, the first recess 235 is coaxially disposed with the liquid injection hole 233 .

[0089] It should be noted that the first recess 235 can be completely located in the first protrusion 232, or can be partially recessed into the cover body 231. If the first recess 235 is completely located in the first protrusion 232, in the thickness direction Z of the end cover 23, the distance from the bottom surface of the first recess 235 to the abutment surface 2321 of the first protrusion 232 is not greater than the distance from the inner surface of the cover body 231 to the abutment surface 2321 of the first protrusion 232. Figure 5 As shown, if a portion of the first recess 235 is recessed into the cover body 231, in the thickness direction Z of the end cover 23, the distance from the bottom surface of the first recess 235 to the abutment surface 2321 of the first convex portion 232 is greater than the distance from the inner surface of the cover body 231 to the abutment surface 2321 of the first convex portion 232, so that the depth of the first recess 235 is deeper and can accommodate more electrolyte.

[0090] In some embodiments, the two ends of the guide channel 234 respectively pass through the outer peripheral surface of the first protrusion 232 and the inner peripheral surface of the first recess 235, which is conducive to the electrolyte entering the guide channel 234 from the first recess 235 and facilitating the lateral flow of the electrolyte to the outside of the outer peripheral surface of the first protrusion 232.

[0091] The guide channel 234 can extend in a straight line. The extension direction of the guide channel 234 can be perpendicular to the axis of the injection hole 233, that is, the guide channel 234 extends radially along the injection hole 233. The extension direction of the guide channel 234 can also be set at an acute angle to the axis of the injection hole 233. For example, in the thickness direction Z of the end cover 23, the end of the guide channel 234 passing through the outer peripheral surface of the first protrusion 232 is closer to the electrode assembly 21 than the end of the guide channel 234 passing through the inner peripheral surface of the first recess 235. That is, the end of the guide channel 234 passing through the outer peripheral surface of the first protrusion 232 is lower than the end of the guide channel 234 passing through the inner peripheral surface of the first recess 235, so that the guide channel 234 is in an inclined state, which is conducive to the flow of electrolyte in the guide channel 234. Figure 5 In the embodiment, the guide channel 234 extends along the radial direction of the liquid injection hole 233.

[0092] In other embodiments, both ends of the guide channel 234 respectively pass through the outer peripheral surface of the first protrusion 232 and the bottom surface of the first recess 235. In this embodiment, the guide channel 234 can be a curved channel formed inside the end cover 23.

[0093] In some embodiments, please refer to Figure 5 The end cap 23 has a liquid outlet surface 236. One end of the liquid injection hole 233 passes through the liquid outlet surface 236, and the liquid outlet surface 236 is located in the first recess 235. In the thickness direction Z of the end cap 23, the liquid outlet surface 236 is farther away from the electrode assembly 21 than the abutment surface 2321. This creates a distance between the liquid outlet surface 236 and the electrode assembly 21, facilitating the entry of the electrolyte from the liquid injection hole 233 into the first recess 235, facilitating the immersion of the electrolyte into the electrode assembly 21, and facilitating lateral flow of the electrolyte.

[0094] Optionally, in the thickness direction Z of the end cover 23 , the guide channel 234 is overall closer to the electrode assembly 21 than the liquid outlet surface 236 , so that there is a larger distance between the liquid outlet surface 236 and the electrode assembly 21 , and the electrolyte can more easily enter the guide channel 234 .

[0095] Optionally, the end cap 23 may further include a second protrusion 237, which is located within the first recess 235 and protrudes from the bottom surface of the first recess 235 in a direction facing the electrode assembly 21. A liquid outlet surface 236 is formed at the end of the second protrusion 237 facing the electrode assembly 21. The second protrusion 237 can reinforce the location of the liquid injection hole 233 on the end cap 23, thereby improving the strength of the location of the liquid injection hole 233 on the end cap 23.

[0096] In some embodiments, the electrode assembly 21 has a center hole 214. In the thickness direction Z of the end cover 23, the center hole 214 is arranged opposite to the injection hole 233. In the process of injecting electrolyte into the battery cell 20 through the injection hole 233, the electrolyte entering the injection hole 233 can quickly flow into the center hole 214 to infiltrate the electrode plates in the electrode assembly 21.

[0097] It should be noted that in the thickness direction Z of the end cover 23 , the center hole 214 and the injection hole 233 are arranged opposite to each other, that is, in the thickness direction Z of the end cover 23 , the projection of the hole wall of the injection hole 233 is at least partially located in the center hole 214 .

[0098] Exemplarily, the center hole 214 is coaxially arranged with the injection hole 233, and the aperture of the injection hole 233 is smaller than the aperture of the center hole 214, so that the projection of the hole wall of the injection hole 233 in the thickness direction Z of the end cover 23 is completely located in the center hole 214, making it easier for the electrolyte to enter the center hole 214 from the injection hole 233 to infiltrate the electrode.

[0099] In some embodiments, the end cap 23 may further include a third protrusion 238 that protrudes from the outer surface of the cap body 231 in a direction away from the electrode assembly 21. In the thickness direction Z of the end cap 23, the projection of the third protrusion 238 completely covers the first recess 235. The third protrusion 238 can reinforce the location of the end cap 23 where the first recess 235 is provided, thereby increasing the strength of the end cap 23 where the first recess 235 is provided.

[0100] Exemplarily, the third protrusion 238 is a cylindrical structure.

[0101] In some embodiments, the second retaining portion 224 of the housing 22 is located on the outer periphery of the third protrusion 238, that is, the third protrusion 238 is located inside the inner circumference of the second retaining portion 224. The second retaining portion 224 and the third protrusion 238 respectively serve as the two output poles of the battery cell 20. The output pole is the portion of the battery cell 20 that connects to other components and outputs electrical energy. The second retaining portion 224 can serve as the positive output pole of the battery cell 20, and the third protrusion 238 as the negative output pole of the battery cell 20; alternatively, the second retaining portion 224 can serve as the negative output pole of the battery cell 20, and the third protrusion 238 can serve as the positive output pole of the battery cell 20. For example, in the case of two battery cells 20 being electrically connected via a busbar to achieve series connection, the second retaining portion 224 of one battery cell 20 and the third protrusion 238 of the other battery cell 20 are both connected to the same busbar, for example, by welding.

[0102] Optionally, the outer surface of the second limiting portion 224 (the surface of the second limiting portion 224 facing away from the cover body 231 in the thickness direction Z of the end cover 23) is flush with the outer surface of the third protrusion 238 (the surface of the third protrusion 238 facing away from the cover body 231 in the thickness direction Z of the end cover 23) to facilitate the connection between the second limiting portion 224 and the third protrusion 238 and the confluence component.

[0103] In some embodiments, the battery cell 20 further includes a sealing member 24 for sealing the liquid injection hole 233. A second recess 239 is provided on the end cap 23. The second recess 239 is recessed from the outer surface of the third protrusion 238 in a direction facing the electrode assembly 21. The second recess 239 is used to accommodate the sealing member 24, thereby concealing the sealing member 24 and preventing it from interfering with the connection between the third protrusion 238 and the current collector.

[0104] Illustratively, two ends of the liquid injection hole 233 pass through the liquid outlet surface 236 and the bottom surface of the second recess 239 respectively.

[0105] In some embodiments, please refer to Figure 6 , Figure 6 for Figure 5 As shown in the structural diagram of the end cover 23, the guide channel 234 is a guide groove provided at the end of the first protrusion 232 away from the cover body 231, which facilitates the molding of the guide channel 234. In actual production, the guide groove can be directly processed on the abutment surface 2321.

[0106] In addition, since the side of the guide groove facing the electrode assembly 21 is open, a portion of the electrolyte flowing in the guide channel 234 can flow directly into the interior of the electrode assembly 21, which facilitates the electrolyte to enter the interior of the electrode assembly 21 to infiltrate the electrode plate, and can effectively improve the wetting effect on the electrode assembly 21.

[0107] Exemplarily, the guide groove is provided on the abutting surface 2321 of the first protrusion 232 .

[0108] In some embodiments, the guide channel 234 extends radially along the injection hole 233 to facilitate the electrolyte to enter the guide channel 234 and improve the injection efficiency.

[0109] Taking the first recess 235 formed on the end cover 23 as an example, the two ends of the guide channel 234 in the radial direction of the liquid injection hole 233 respectively penetrate the outer circumferential surface of the first convex portion 232 and the inner circumferential surface of the first recess 235 .

[0110] In the embodiment of the present application, the number of the guide channel 234 on the first protrusion 232 may be one or more.

[0111] In some embodiments, please refer to Figure 6 The first convex portion 232 is provided with a plurality of guide channels 234 arranged circumferentially with the injection hole 233 as the center, so that the electrolyte can flow in multiple different directions through the plurality of guide channels 234, further improving the injection efficiency.

[0112] For example, in Figure 6 In the embodiment, the first convex portion 232 is provided with four guide channels 234 arranged circumferentially with the liquid injection hole 233 as the center. The angle between each two adjacent guide channels 234 is 90 degrees.

[0113] In some embodiments, please refer to Figure 7 , Figure 7 for Figure 4 As shown in the partial enlarged view of the battery cell 20, the battery cell 20 may also include an insulating member 25, which is used to isolate the end cover 23 and the shell 22 to achieve an insulated connection between the end cover 23 and the shell 22, so as to reduce the risk of short circuit caused by contact between the end cover 23 and the shell 22.

[0114] The insulating member 25 can be made of insulating materials such as plastic, rubber, etc.

[0115] Exemplarily, the insulating member 25 is disposed between the peripheral wall 222 of the shell 22 and the cover body 231 of the end cover 23 to separate the cover body 231 from the peripheral wall 222 of the shell 22 , thereby achieving an insulated connection between the end cover 23 and the shell 22 .

[0116] It should be noted that the insulating member 25 between the end cover 23 and the housing 22 may only play an insulating role, or may play an insulating role and a sealing role at the same time, so as to achieve sealing between the end cover 23 and the housing 22 .

[0117] In some embodiments, the insulating member 25 includes a first connecting portion 251, a second connecting portion 252, a third connecting portion 253, and a fourth connecting portion 254, which are connected in sequence. In the thickness direction Z of the end cap 23, the first connecting portion 251 and the third connecting portion 253 are located on either side of the cap body 231. The cap body 231 presses the third connecting portion 253 against the first limiting portion 223, and the second limiting portion 224 presses the first connecting portion 251 against the cap body 231. The second connecting portion 252 is located between the outer circumference of the cap body 231 and the inner circumference of the housing 22. The fourth connecting portion 254 is located between the outer circumference of the first protrusion 232 and the inner circumference of the first limiting portion 223. The fourth connecting portion 254 serves to separate the first protrusion 232 and the first limiting portion 223, thereby reducing the risk of a short circuit caused by contact between the first protrusion 232 and the first limiting portion 223.

[0118] The first connection portion 251 , the second connection portion 252 , the third connection portion 253 and the fourth connection portion 254 may all be annular structures.

[0119] The present invention provides a method for manufacturing a battery cell 20. Figure 8 , Figure 8 This is a flow chart of a method for manufacturing a battery cell 20 provided in some embodiments of the present application. The manufacturing method includes:

[0120] S100: Providing an electrode assembly 21, wherein the electrode assembly 21 has a first electrode tab 211;

[0121] S200: Providing a housing 22 having an opening;

[0122] S300: providing an end cap 23;

[0123] S400: accommodating the electrode assembly 21 in the housing 22;

[0124] S500: Cover the end cover 23 with the opening of the housing 22;

[0125] The end cap 23 includes a cover body 231 and a first protrusion 232. The cover body 231 is used to connect to the housing 22 and cover the opening. The first protrusion 232 protrudes from the inner surface of the cover body 231 in a direction facing the electrode assembly 21. The first protrusion 232 is used to abut against the first electrode tab 211. The end cap 23 is provided with an injection hole 233. The injection hole 233 is used to allow electrolyte to enter the battery cell 20 from the outside of the battery cell 20. The injection hole 233 is located on the inner side of the outer peripheral surface of the first protrusion 232. The first protrusion 232 is provided with a guide channel 234. The guide channel 234 is connected to the injection hole 233 and extends through the outer peripheral surface. The guide channel 234 is used to allow electrolyte entering the injection hole 233 to flow outside the outer peripheral surface.

[0126] In the above method, the order of step S100, step S200 and step S300 is not limited. For example, step S300 may be performed first, then step S200, and then step S100.

[0127] It should be noted that the relevant structures of the battery cells 20 manufactured by the manufacturing methods provided in the above embodiments can refer to the battery cells 20 provided in the above embodiments, and will not be described in detail here.

[0128] In addition, the present invention also provides a manufacturing device 2000 for a battery cell 20, please refer to Figure 9 , Figure 9 This is a schematic block diagram of a manufacturing apparatus 2000 for a battery cell 20 provided in some embodiments of the present application. The manufacturing apparatus 2000 includes a first providing device 2100 , a second providing device 2200 , a third providing device 2300 , and an assembling device 2400 .

[0129] The first providing device 2100 is used to provide an electrode assembly 21 having a first electrode tab 211. The second providing device 2200 is used to provide a housing 22 having an opening. The third providing device 2300 is used to provide an end cap 23. The assembly device 2400 is used to accommodate the electrode assembly 21 in the housing 22. The assembly device 2400 is also used to cover the end cap 23 with the opening.

[0130] The end cap 23 includes a cover body 231 and a first protrusion 232. The cover body 231 is used to connect to the housing 22 and cover the opening. The first protrusion 232 protrudes from the inner surface of the cover body 231 in a direction facing the electrode assembly 21. The first protrusion 232 is used to abut against the first electrode tab 211. The end cap 23 is provided with an injection hole 233. The injection hole 233 is used to allow electrolyte to enter the battery cell 20 from the outside of the battery cell 20. The injection hole 233 is located on the inner side of the outer peripheral surface of the first protrusion 232. The first protrusion 232 is provided with a guide channel 234. The guide channel 234 is connected to the injection hole 233 and extends through the outer peripheral surface. The guide channel 234 is used to allow electrolyte entering the injection hole 233 to flow outside the outer peripheral surface.

[0131] It should be noted that the relevant structures of the battery cells 20 manufactured by the manufacturing equipment 2000 provided by the above embodiment can refer to the battery cells 20 provided by the above embodiments, and will not be repeated here.

[0132] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0133] The above embodiments are intended only to illustrate the technical solutions of this application and are not intended to limit this application. Those skilled in the art will appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application are intended to be within the scope of protection of this application.

Claims

1. A battery cell, characterized in that: include: An electrode assembly having a first tab; a shell having an opening, wherein the shell is used to accommodate the electrode assembly; as well as an end cap, comprising a cap body and a first protrusion, wherein the cap body is used to connect to the housing and cover the opening, and the first protrusion protrudes from the inner surface of the cap body in a direction facing the electrode assembly and abuts against the first tab; The end cover is provided with a liquid injection hole, which is used to allow electrolyte to enter the interior of the battery cell from the outside of the battery cell, and the liquid injection hole is located on the inner side of the outer peripheral surface of the first convex portion. The first convex portion is provided with a guide channel, the guide channel is connected to the injection hole and passes through the outer peripheral surface, and the guide channel is used to allow at least part of the electrolyte to flow outside the outer peripheral surface; The electrode assembly has a central hole. In the thickness direction of the end cover, the central hole is arranged opposite to the injection hole, and the diameter of the injection hole is smaller than the diameter of the central hole.

2. The battery cell according to claim 1, wherein: The first protrusion has an abutting surface at one end away from the cover body, and the abutting surface is used to abut against the first tab; and The end cover is provided with a first recessed portion, which is formed by the abutting surface being recessed in a direction away from the electrode assembly, and the injection hole is connected with the guide channel through the first recessed portion.

3. The battery cell according to claim 2, characterized in that: Two ends of the guide channel respectively penetrate the outer circumferential surface and the inner circumferential surface of the first recess.

4. The battery cell according to claim 2, characterized in that: The end cover has a liquid outlet surface, one end of the liquid injection hole passes through the liquid outlet surface, and the liquid outlet surface is located in the first recess; and In the thickness direction of the end cover, the liquid outlet surface is farther away from the electrode assembly than the abutting surface.

5. The battery cell according to claim 4, characterized in that In the thickness direction of the end cover, the guide channel as a whole is closer to the electrode assembly than the liquid outlet surface.

6. The battery cell according to claim 4, characterized in that The end cap further comprises: The second convex portion is located in the first concave portion and protrudes from the bottom surface of the first concave portion in a direction facing the electrode assembly. The liquid outlet surface is formed at one end of the second convex portion facing the electrode assembly.

7. The battery cell according to any one of claims 1 to 6, characterized in that: The guide channel is a guide groove, and the guide groove is arranged at an end of the first protrusion away from the cover body.

8. The battery cell according to any one of claims 1 to 6, characterized in that: The first convex portion is provided with a plurality of the guide channels, and the plurality of the guide channels are arranged at intervals along the circumferential direction with the liquid injection hole as the center.

9. The battery cell according to any one of claims 1 to 6, characterized in that: The guide channel extends along the radial direction of the liquid injection hole.

10. The battery cell according to any one of claims 1 to 6, characterized in that: The liquid injection hole is coaxially arranged with the first convex portion.

11. A battery, characterized in that: include: The battery cell according to any one of claims 1 to 10; as well as The box is used to accommodate the battery cells.

12. An electrical device, characterized in that: Comprising a battery according to claim 11.

13. A method for manufacturing a battery cell, characterized in that: include: Providing an electrode assembly, the electrode assembly having a first tab; providing a housing having an opening; Provide end caps; accommodating the electrode assembly in the housing; as well as Making the end cover cover the opening; In which, the end cover includes a cover body and a first protrusion, the cover body is used to connect with the shell and cover the opening, the first protrusion protrudes from the inner surface of the cover body in the direction facing the electrode assembly, and the first protrusion is configured to abut against the first pole ear; the end cover is provided with an injection hole, the injection hole is used to allow electrolyte to enter the interior of the battery cell from the outside of the battery cell, and the injection hole is located on the inner side of the outer peripheral surface of the first protrusion; the first protrusion is provided with a guide channel, the guide channel is connected with the injection hole and passes through the outer peripheral surface, the guide channel is used to allow the electrolyte entering the injection hole to flow to the outside of the outer peripheral surface, the electrode assembly has a center hole, and in the thickness direction of the end cover, the center hole and the injection hole are arranged opposite to each other, and the diameter of the injection hole is smaller than the diameter of the center hole.

14. A battery cell manufacturing device, characterized in that: include: A first providing device is configured to provide an electrode assembly, wherein the electrode assembly has a first electrode tab; A second providing device is configured to provide a housing having an opening; a third providing device configured to provide an end cap; as well as an assembling device configured to accommodate the electrode assembly in the housing and to cover the opening with the end cap; In which, the end cover includes a cover body and a first protrusion, the cover body is used to connect with the shell and cover the opening, the first protrusion protrudes from the inner surface of the cover body in the direction facing the electrode assembly, and the first protrusion is configured to abut against the first pole ear; the end cover is provided with an injection hole, the injection hole is used to allow the electrolyte to flow from the outside of the battery cell into the inside of the battery cell, and the injection hole is located on the inner side of the outer peripheral surface of the first protrusion; the first protrusion is provided with a guide channel, the guide channel is connected with the injection hole and passes through the outer peripheral surface, the guide channel is used to allow the electrolyte entering the injection hole to flow to the outside of the outer peripheral surface, the electrode assembly has a center hole, and in the thickness direction of the end cover, the center hole and the injection hole are arranged opposite to each other, and the diameter of the injection hole is smaller than the diameter of the center hole.

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