Battery cell and manufacturing method therefor, battery cell manufacturing device, battery, and electric apparatus

Abstract

The present application is applicable to the technical field of batteries, and provides a battery cell and a manufacturing method therefor, a battery cell manufacturing device, a battery, and an electric apparatus. The battery cell (100) comprises a casing (10) and an electrode assembly. The casing (10) comprises an end cover (12). The end cover (12) comprises a first groove (112) and an electrolyte injection hole structure (111) arranged in the first groove (112). The electrolyte injection hole structure (111) comprises an electrolyte injection hole (1111) and a surrounding rim (1112) arranged around the electrolyte injection hole (1111). The size of the outer edge of the first groove (112) is greater than that of the outer edge of the surrounding rim (1112). The surrounding rim (1112) is used for covering an electrolyte injection barrier layer (20). The battery cell provided in embodiments of the present application can mitigate the problem of an electrolyte contaminating the casing during electrolyte injection.

Description

Battery cell, manufacturing method thereof, battery cell manufacturing device, battery, and electric device

[0001] This application claims priority to the Chinese patent application No. 202410796035.4, filed on June 19, 2024, and entitled "Battery cell, manufacturing method thereof, battery cell manufacturing device, battery, and electric device", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of batteries, in particular to a battery cell, a manufacturing method thereof, a battery cell manufacturing device, a battery, and an electric device. BACKGROUND

[0003] Energy saving and emission reduction is the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their energy-saving and environmentally friendly advantages. For electric vehicles, battery technology is an important factor for their development.

[0004] The lithium battery used by an electric vehicle is generally referred to as a power battery. The battery cell in the power battery generally includes a shell and an electrode assembly sealed in the shell. The shell is provided with a liquid injection hole. In the process of injecting electrolyte, an injection nozzle is arranged on the liquid injection hole to inject electrolyte into the shell. After the injection, the injection nozzle is lifted, and the electrolyte on the injection nozzle is easy to drop around the liquid injection hole, causing electrolyte pollution, and then affecting the welding efficiency and welding quality of the subsequent sealing nail on the liquid injection hole.

[0005] SUMMARY

[0006] Therefore, the embodiments of the present application provide a battery cell, a manufacturing method thereof, a battery cell manufacturing device, a battery, and an electric device to improve the problem of electrolyte pollution of the shell in the liquid injection process.

[0007] The embodiments of the first aspect of the present application provide a battery cell, comprising: a shell, the shell comprising an end cover, the end cover comprising a first groove and a liquid injection hole structure arranged in the first groove, the liquid injection hole structure comprising a liquid injection hole and a surrounding edge arranged around the liquid injection hole, the outer edge size of the first groove being greater than the outer edge size of the surrounding edge, and the surrounding edge being used to cover a liquid injection barrier layer; and an electrode assembly accommodated in the shell.

[0008] The battery cell provided by the embodiments of the present application has the following advantages. The end cover of the shell comprises a first groove and a liquid injection hole structure arranged in the first groove. The liquid injection hole structure comprises a liquid injection hole and a surrounding edge arranged around the liquid injection hole. The outer edge size of the first groove is greater than the outer edge size of the surrounding edge. In this way, a gap is arranged between the surrounding edge and the outer edge of the first groove. During liquid injection, the liquid injection barrier layer can be wrapped on the surrounding edge, so that the liquid injection barrier layer can isolate the electrolyte from the shell. After the electrolyte drops, the electrolyte can fall on the liquid injection barrier layer and will not directly drop on the shell. The above battery cell can reduce the risk of electrolyte dropping on the surface of the shell during the liquid injection process, that is, the risk of electrolyte pollution is reduced, and thus the problem of affecting the welding efficiency and welding quality of the sealing nail due to electrolyte pollution is improved. At the same time, the liquid injection barrier layer can be stably wrapped on the surrounding edge and is not easy to fall off or shift. In addition, under the liquid injection pressure, the electrolyte is not easy to flow between the liquid injection barrier layer and the inner wall of the liquid injection hole, further reducing the risk of electrolyte pollution.

[0009] In some embodiments, the liquid injection hole comprises a counterbore part and a liquid inlet part in communication, the hole diameter of the counterbore part is greater than the hole diameter of the liquid inlet part, and the liquid inlet part penetrates through the end cover; and the surrounding edge surrounds the counterbore part.

[0010] By adopting the above technical solution, the counterbore part can position the liquid injection nozzle, and the liquid inlet part is used for liquid injection. The surrounding edge surrounds the counterbore part. In this way, the liquid injection barrier layer wrapped on the surrounding edge can have a comprehensive barrier protection effect on the liquid injection hole, reducing the risk of electrolyte pollution.

[0011] In some embodiments, the surrounding edge comprises a first outer surface and a first inner surface arranged oppositely, and a first top surface connected between the first outer surface and the first inner surface. The first inner surface is a side wall of the counterbore part. The first outer surface and the first inner surface are perpendicular to the first top surface, respectively.

[0012] By adopting the above technical solution, the liquid injection barrier layer can be bent twice on the surrounding edge and form two 90-degree bending angles. The liquid injection barrier layer can be stably wrapped on the surrounding edge.

[0013] In some embodiments, the first top surface is flush with the outer surface of the end cover.

[0014] By adopting the above technical solution, when the end cover is manufactured, only the liquid injection hole and the first groove need to be manufactured, and the surrounding edge can be formed between the first groove and the liquid injection hole. No additional surrounding edge needs to be manufactured. The manufacturing method of the shell is simple, and the cost is low.

[0015] The second aspect of the application provides a method for manufacturing a battery cell, comprising: placing an electrode assembly in a shell, the shell comprising an end cover, the end cover comprising a first groove and a liquid injection hole structure arranged in the first groove, the liquid injection hole structure comprising a liquid injection hole and a surrounding edge arranged around the liquid injection hole, the outer edge size of the first groove being larger than the outer edge size of the surrounding edge; covering a liquid injection barrier layer, so that the liquid injection barrier layer is covered on the surrounding edge and the liquid injection barrier layer is attached to the inner wall of the liquid injection hole; and injecting electrolyte into the shell through the liquid injection hole.

[0016] In the method for manufacturing a battery cell provided by the embodiments of the application, the shell of the battery cell is formed with a liquid injection hole, a surrounding edge surrounding the liquid injection hole, and a first groove, the outer edge size of the first groove being larger than the outer edge size of the surrounding edge, i.e., a gap can be formed between the surrounding edge and the side wall of the first groove, so that the liquid injection barrier layer can be conveniently covered on the surrounding edge and attached to the inner wall of the liquid injection hole, i.e., the liquid injection hole can be covered by the liquid injection barrier layer, and the liquid injection barrier layer can block the pollution of the electrolyte.

[0017] The barrier layer is a heat-shrinkable film, and the covering of the liquid injection barrier layer comprises: placing the liquid injection barrier layer on the liquid injection hole structure, the liquid injection barrier layer comprising a liquid injection barrier portion and a positioning portion arranged at one end of the liquid injection barrier portion, a through hole being arranged in the liquid injection barrier portion, and the positioning portion extending outward from the edge of the liquid injection barrier portion; the liquid injection barrier portion is arranged in the liquid injection hole, and the positioning portion is arranged above the surrounding edge; and performing heat shrinkage treatment on the liquid injection barrier layer, so that the positioning portion is covered on the surrounding edge and the liquid injection barrier portion is attached to the inner wall of the liquid injection hole.

[0018] By adopting the above technical solution, the liquid injection barrier layer is a heat-shrinkable film, and the liquid injection barrier layer can be formed by heat shrinkage treatment, so that the positioning portion is tightly wrapped on the surrounding edge and the liquid injection barrier portion is tightly attached to the inner wall of the liquid injection hole, the electrolyte is not easy to flow between the liquid injection barrier layer and the liquid injection hole during the liquid injection process, the barrier protection effect is further improved, and the risk of electrolyte pollution is further reduced.

[0019] In some embodiments, the heat shrinkage treatment on the liquid injection barrier layer comprises: pressing a hot press head on the liquid injection barrier layer and the liquid injection hole structure, so that the liquid injection barrier layer is deformed; and heating the liquid injection barrier layer by using the hot press head to perform heat shrinkage treatment on the liquid injection barrier layer.

[0020] By adopting the above technical solution, the liquid injection barrier layer is deformed and shrunk by using the hot press head to apply pressure and heat to the liquid injection barrier layer, the efficiency of the heat shrinkage treatment is high, and the heat shrinkage effect is good.

[0021] In some embodiments, the liquid injection hole comprises a counterbore part and a liquid inlet part in communication, the counterbore part has a larger hole diameter than the liquid inlet part; the hot pressing head comprises a hot pressing body and an extension rod, one end of the hot pressing body is provided with a forming table and a forming groove surrounding the forming table, and the extension rod is protruding on the forming table; when the hot pressing head is pressed on the liquid injection barrier layer and the liquid injection hole structure, the forming groove accommodates the surrounding edge, the forming table is pressed on the counterbore part, and the extension rod extends into the liquid inlet part.

[0022] By adopting the above technical solution, the end of the hot pressing body facing the extension rod is shaped with the liquid injection hole and the surrounding edge of the shell, and the hot pressing body is pressed on the liquid injection barrier layer and the shell, so that the liquid injection barrier layer is deformed to fit the shape of the surrounding edge and the liquid injection hole.

[0023] In some embodiments, a plurality of air blowing holes are arranged on the hot pressing body, and the air blowing holes are distributed on the forming groove and the forming table; the hot pressing head is used to heat the liquid injection barrier layer, which comprises blowing hot air towards the liquid injection barrier layer through the air blowing holes.

[0024] By adopting the above technical solution, the hot pressing body performs heat shrinkage treatment on the liquid injection barrier layer through the air blowing heat shrinkage process, which can realize rapid and efficient shrinkage operation and improve the uniformity of the shrinkage of the liquid injection barrier layer, so that the liquid injection barrier layer can be tightly attached to the surrounding edge and the counterbore part.

[0025] In some embodiments, after the electrolyte is injected into the shell, the manufacturing method further comprises: cutting the liquid injection barrier layer by laser and removing the liquid injection barrier layer. By adopting the above technical solution, the liquid injection barrier layer is cut by laser, which can reduce the binding force of the liquid injection barrier layer on the shell, facilitate the removal of the liquid injection barrier layer, and prevent the liquid injection barrier layer from interfering with the subsequent welding of the sealing nail.

[0026] In some embodiments, the liquid injection barrier layer is cut by laser and removed, which comprises: cutting the liquid injection barrier layer along the surrounding edge to divide the liquid injection barrier layer into a first film and a second film; and removing the first film and the second film by a vacuum adsorption device.

[0027] By adopting the above technical solution, the removal step of the liquid injection barrier layer has high automation, and the efficiency of the liquid injection process is improved.

[0028] Embodiments of the third aspect of the present application propose a battery cell manufacturing device, which comprises a hot pressing head for covering a liquid injection barrier layer on a shell of a battery cell.

[0029] The battery cell manufacturing device provided by the embodiments of the present application comprises a hot pressing head, the hot pressing head can wrap the liquid injection barrier layer on the shell of the battery cell, during the liquid injection process, the liquid injection barrier layer can isolate the electrolyte from the shell, the electrolyte dropped from the liquid injection nozzle can fall on the liquid injection barrier layer and cannot directly drop on the shell, thereby reducing the risk of electrolyte polluting the shell.

[0030] In some embodiments, the hot pressing head comprises a hot pressing body and an extension rod, one end of the hot pressing body is provided with a forming table and a forming groove surrounding the forming table, the extension rod is protruded on the forming table, and the hot pressing body is used for hot pressing the liquid injection barrier layer to make the liquid injection barrier layer shrink and wrap on the shell.

[0031] By adopting the above technical solution, the hot pressing body can deform the liquid injection barrier layer to fit the shell, and the extension rod can avoid the liquid injection barrier layer from being raised.

[0032] In some embodiments, a plurality of air blowing holes are arranged on the hot pressing body and are distributed on the forming groove and the forming table. By adopting the above technical solution, the hot pressing body can realize fast and efficient shrinkage operation by using the air blowing shrinkage process to heat-shrink the liquid injection barrier layer, and the uniformity of the shrinkage of the liquid injection barrier layer is improved.

[0033] In some embodiments, the forming groove is a circular annular groove. By adopting the above technical solution, the forming groove can wrap the liquid injection barrier layer on the circumferential side of the surrounding edge, improve the wrapping integrity of the liquid injection barrier layer, and the liquid injection barrier layer can isolate the pollution of the electrolyte along the circumferential direction of the liquid injection hole.

[0034] The embodiments of the fourth aspect of the present application provide a battery comprising the battery cell provided by the first aspect, the battery cell manufactured by the manufacturing method of the battery cell provided by the second aspect.

[0035] The embodiments of the fifth aspect of the present application provide a power consuming device comprising the battery provided by the fourth aspect, and the battery is used for providing electric energy.

[0036] The above description is only a summary of the technical solutions of the present application, in order to more clearly understand the technical means of the present application, the specific embodiments of the present application can be implemented according to the content of the description, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the conventional description will be briefly introduced. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor.

[0038] Fig. 1 is a structural schematic diagram of a vehicle according to an embodiment of the present application;

[0039] Fig. 2 is a structural schematic diagram of a battery according to an embodiment of the present application;

[0040] Fig. 3 is a structural schematic diagram of a battery cell in some prior art cases;

[0041] Fig. 4 is a structural schematic diagram of the battery cell and a liquid injection nozzle shown in Fig. 3;

[0042] Fig. 5A is a structural schematic diagram of an end cover in a battery cell according to an embodiment of the present application;

[0043] Fig. 5B is a top view of the end cover shown in Fig. 5A;

[0044] Fig. 5C is a sectional view of the end cover shown in Fig. 5B along line A-A;

[0045] Fig. 6 is a structural schematic diagram of the end cover shown in Fig. 5A after a liquid injection barrier layer is coated thereon;

[0046] Fig. 7 is a flow chart of a manufacturing method of a battery cell according to an embodiment of the present application;

[0047] Fig. 8A is a structural schematic diagram of a liquid injection barrier layer according to an embodiment of the present application;

[0048] Fig. 8B is a side view of the liquid injection barrier layer shown in Fig. 8A;

[0049] Fig. 8C is a top view of the liquid injection barrier layer shown in Fig. 8A;

[0050] Fig. 8D is a sectional view of the liquid injection barrier layer shown in Fig. 8C along line B-B;

[0051] Fig. 9A is a structural schematic diagram of a liquid injection barrier layer before heat shrinking according to an embodiment of the present application;

[0052] Fig. 9B is a top view of the liquid injection barrier layer shown in Fig. 9A;

[0053] Fig. 9C is a sectional view of the liquid injection barrier layer shown in Fig. 9B along line C-C;

[0054] Fig. 10 is an exploded schematic diagram of a heat press head and a liquid injection barrier layer according to an embodiment of the present application;

[0055] Fig. 11 is a schematic view of a hot press head according to an embodiment of the present application;

[0056] Fig. 12A is a schematic view of an assembly of a hot press head and a liquid injection barrier according to an embodiment of the present application;

[0057] Fig. 12B is a side view of the hot press head and the liquid injection barrier shown in Fig. 12A;

[0058] Fig. 12C is a sectional view of the hot press head and the liquid injection barrier shown in Fig. 12B along line D-D;

[0059] Fig. 13 is a schematic view of a laser cutting step of a liquid injection barrier according to an embodiment of the present application;

[0060] Fig. 14A is a schematic view of a first film in a liquid injection barrier according to an embodiment of the present application;

[0061] Fig. 14B is a schematic view of a second film in a liquid injection barrier according to an embodiment of the present application.

[0062] The meanings of the reference signs are as follows: 1000, vehicle; 1, battery; 2, controller; 3, motor; 200, case; 210, first portion; 220, second portion; 300, liquid injection nozzle; 100, battery cell; 10, housing; 11, end cover; 12, housing main body; 111, liquid injection hole structure; 1111, liquid injection hole; 1111a, counterbore portion; 1111b, liquid inlet portion; 1112, rim; 1112a, first outer surface; 1112b, first inner surface; 1112c, first top surface; 112, first groove; 20, liquid injection barrier; 21, liquid injection barrier portion; 22, positioning portion; 23, laser cutting line; 23a, first film; 23b, second film; 30, hot press head; 31, hot press body; 311, shaped groove; 312, shaped land; 313, air blowing hole; 32, extension rod. Embodiments of the present application

[0063] Embodiments of the technical solutions of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot be used to limit the protection scope of the present application.

[0064] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the specification herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application; the terms "including" and "comprising" and any variations thereof herein are intended to cover the inclusion of the stated elements but not the exclusion of other elements. The terms "including" and "comprising" and any variations thereof herein are intended to cover the inclusion of the stated elements but not the exclusion of other elements.

[0065] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise explicitly specified and limited.

[0066] Reference to "embodiments" herein means that the specific features, structures or properties described in conjunction with the embodiments can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0067] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which means that there are three cases of A alone, A and B together, and B alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after it.

[0068] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), and similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0069] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the embodiments of the present application and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0070] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection", "fixing" and the like should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0071] The battery cell in the power battery usually comprises a shell and an electrode assembly sealed in the shell. The shell is provided with a liquid injection hole, and a liquid injection nozzle is arranged on the liquid injection hole to inject electrolyte into the shell during the electrolyte injection process. After the electrolyte injection, the liquid injection nozzle is lifted, and the electrolyte on the liquid injection nozzle is easy to drop around the liquid injection hole, causing electrolyte pollution. After the electrolyte injection is completed, a sealing nail needs to be welded on the shell to seal the liquid injection hole. However, the electrolyte dropped around the liquid injection hole will affect the welding efficiency and welding quality of the sealing nail on the liquid injection hole.

[0072] In order to improve the problem of electrolyte pollution during the electrolyte injection process, the application provides a battery cell and a manufacturing method thereof, a battery and a power utilization device. The battery cell comprises a shell and an electrode assembly, and the electrode assembly is contained in the shell; the shell comprises an end cover, the end cover comprises a first groove and a liquid injection hole structure arranged in the first groove, the liquid injection hole structure comprises a liquid injection hole and a surrounding edge arranged around the liquid injection hole, the outer edge size of the first groove is greater than the outer edge size of the surrounding edge, and the surrounding edge is used to cover a liquid injection barrier layer. In the battery cell provided by the embodiments of the application, the liquid injection hole structure comprises a liquid injection hole and a surrounding edge around the liquid injection hole, and the outer edge size of the first groove is greater than the outer edge size of the surrounding edge. In this way, a gap is arranged between the surrounding edge and the first groove, and the liquid injection barrier layer can be covered on the surrounding edge during the electrolyte injection, so that the liquid injection barrier layer can isolate the electrolyte from the shell, and the electrolyte dropped from the liquid injection nozzle can fall on the liquid injection barrier layer and will not directly drop on the shell. Therefore, the above-mentioned battery cell can reduce the risk of electrolyte dropping on the surface of the shell during the electrolyte injection process, that is, the risk of electrolyte pollution of the shell is reduced, and the problem of affecting the welding efficiency and welding quality of the sealing nail due to electrolyte pollution is improved.

[0073] Embodiments of the application provide a battery cell. The battery cell disclosed by the embodiments of the application can be used in a power utilization device using a battery as a power source or a variety of energy storage systems using a battery as an energy storage element. The power utilization device can be, but is not limited to, a mobile phone, a tablet computer, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric automobile, a ship, a spacecraft, etc. The electric toy can include a fixed or mobile electric toy, such as a game console, an electric automobile toy, an electric ship toy, an electric aircraft toy, etc. The spacecraft can include an airplane, a rocket, a space shuttle, a spacecraft, etc.

[0074] The following embodiments are described by taking a power utilization device in an embodiment of the application as a vehicle 1000 for convenience of description.

[0075] Please refer to FIG. 1, which is a structural schematic diagram of a vehicle 1000 provided by some embodiments of the present application. The vehicle 1000 can be a fuel automobile, a gas automobile, or a new energy automobile, which can be a pure electric automobile, a hybrid automobile, or a range extended automobile, etc. The vehicle 1000 is internally provided with a battery 1, which can be arranged at the bottom, the head, or the tail of the vehicle 1000. The battery 1 can be used for power supply of the vehicle 1000, for example, the battery 1 can be used as an operating power source of the vehicle 1000. The vehicle 1000 can further include a controller 2 and a motor 3, the controller 2 being used to control the battery 1 to supply power to the motor 3, for example, to meet the power demand of the vehicle 1000 during starting, navigation, and driving.

[0076] In some embodiments of the present application, the battery 1 can not only be used as an operating power source of the vehicle 1000, but also be used as a driving power source of the vehicle 1000, to replace or partially replace fuel or natural gas to provide driving power for the vehicle 1000.

[0077] Please refer to FIG. 1 and FIG. 2, the battery 1 includes a battery monomer 100 and a box body 200, the box body 200 includes a first part 210 and a second part 220, the first part 210 and the second part 220 are mutually covered, and the first part 210 and the second part 220 jointly define an accommodation space for accommodating the battery monomer. The second part 220 can be a hollow structure with one end open, and the first part 210 can be a plate-shaped structure, which is covered on the open side of the second part 220 to jointly define the accommodation space with the second part 220; the first part 210 and the second part 220 can also be hollow structures with one side open, and the open side of the first part 210 is covered on the open side of the second part 220. Of course, the box body 200 formed by the first part 210 and the second part 220 can have various shapes, such as a cylinder, a cuboid, etc.

[0078] The battery monomer 100 can be multiple, and the multiple battery monomers 100 can be connected in series, in parallel, or in a mixed manner. The mixed manner means that the multiple battery monomers 100 are connected in series and in parallel. The multiple battery monomers 100 can be directly connected in series, in parallel, or in a mixed manner, and then the whole formed by the multiple battery monomers 100 is accommodated in the box body 200; of course, the battery 1 can also be that the multiple battery monomers 100 are first connected in series, in parallel, or in a mixed manner to form battery modules, and then the multiple battery modules are connected in series, in parallel, or in a mixed manner to form a whole, which is accommodated in the box body 200. The battery 1 can further include other structures, for example, the battery 1 can further include a current combing component for realizing electrical connection between the multiple battery monomers 100.

[0079] Each of the battery cells 100 can be a secondary battery or a primary battery, and can be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 100 can have a shape of a cylinder, a flat body, a cuboid, or other shapes.

[0080] The battery cell 100 refers to the smallest unit that constitutes the battery 1. As shown in FIG. 3, the battery cell 100 includes a case 10, an electrode assembly, and other functional components.

[0081] The case 10 is a component for forming an internal environment of the battery cell 100, and the formed internal environment can be used to accommodate the electrode assembly, the electrolyte, and other components. The case 10 can have various shapes and sizes, such as a cuboid shape, a cylindrical shape, a hexagonal prism shape, and the like. Specifically, the shape of the case 10 can be determined according to the specific shape and size of the electrode assembly. The material of the case 10 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, and the like, and the present application is not particularly limited thereto.

[0082] Optionally, the case 10 includes a case body and an end cover, and the end cover refers to a component that covers the opening of the case body to isolate the internal environment of the battery cell 100 from the external environment. Without limitation, the shape of the end cover can be adapted to the shape of the case body 12 to fit the case body. The end cover can be provided with functional components such as a pole, etc. The pole can be used to electrically connect with the electrode assembly for outputting or inputting the electrical energy of the battery cell 100. In some embodiments, the end cover can also be provided with a liquid injection port 111 for injecting the electrolyte, and a pressure relief mechanism for relieving the internal pressure of the battery cell 100 when the internal pressure or temperature reaches a threshold value.

[0083] Referring to FIGS. 3, 5A to 6, the embodiment of the first aspect of the present application provides a battery cell 100, which includes a case 10 and an electrode assembly (not shown) accommodated in the case 10, and the case 10 includes an end cover 11, the end cover 11 includes a first groove 112 and a liquid injection hole structure 111 arranged in the first groove 112, the liquid injection hole structure 111 includes a liquid injection hole 1111 and a surrounding edge 1112 arranged around the liquid injection hole 1111, the outer edge size of the first groove 112 is greater than the outer edge size of the surrounding edge 1112, and the surrounding edge 1112 is used to cover the liquid injection barrier layer 20.

[0084] The electrode assembly is a component in which electrochemical reactions occur in the battery cell 100. One or more electrode assemblies can be contained within the casing 10. The electrode assembly is mainly formed by winding or layering a positive electrode sheet and a negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet and the negative electrode sheet have portions with active materials that constitute a main body of the electrode assembly, and portions without active materials that each constitute a tab. The positive electrode tab and the negative electrode tab can be located together at one end of the main body or at opposite ends of the main body. During charging and discharging of the battery, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs connect the electrode terminals to form a current loop.

[0085] The casing 10 includes an end cover 11, and the end cover 11 is provided with a liquid injection hole structure 111 and a first groove 112. The end cover 11 can be a cover plate, and the casing 10 further includes a casing body 12 connected to the end cover 11. In other embodiments, the end cover 11 can also be a side wall of the casing body 12.

[0086] The liquid injection hole structure 111 includes a liquid injection hole 1111 and a surrounding edge 1112. The liquid injection hole 1111 can be circular, and the liquid injection hole 1111 penetrates the end cover 11 to achieve liquid injection. It can be understood that the liquid injection hole 1111 can also be other shapes, such as an oval shape. The surrounding edge 1112 is arranged around the liquid injection hole 1111, i.e. the surrounding edge 1112 is arranged at the periphery of the liquid injection hole 1111. The surrounding edge 1112 provides a basis for the attachment of the liquid injection barrier layer 20, and the surrounding edge 1112 can be an annular structure. It can be understood that the fixing portion 113 can also be other structures, for example, the surrounding edge 1112 includes a plurality of arc-shaped structures that collectively surround the periphery of the liquid injection hole 1111.

[0087] The liquid injection barrier layer 20 is a film layer used to block the electrolyte and the casing 10 during the liquid injection process, and is used to reduce the risk of electrolyte contamination. The liquid injection barrier layer 20 can be a flexible film, such as a heat shrinkable film, or a hard sheet layer, such as a plastic sheet.

[0088] The first groove 112 is arranged on the end cover 11, and the first groove 112 can be a circular groove. In other embodiments, the first groove 112 can also be square, oval or other shapes. The liquid injection hole structure 111 is arranged in the first groove 112. It can be understood that the liquid injection hole 1111 penetrates the groove bottom of the first groove 112. The outer edge size of the first groove 112 is greater than the outer edge size of the surrounding edge 1112. In this way, there is a gap between the outer side wall of the surrounding edge 1112 and the inner side wall of the first groove 112, so as to facilitate the covering of the liquid injection barrier layer 20 on the surrounding edge 1112. For example, in some embodiments, the first groove 112 is circular and the surrounding edge 1112 is circular. The outer edge size of the first groove 112 is greater than the outer edge size of the surrounding edge 1112, which means that the inner diameter of the first groove 112 is greater than the outer diameter of the surrounding edge 1112. It can be understood that the first groove 112 and the surrounding edge 1112 can also be other structures, as long as at least part of the outer edge of the surrounding edge 1112 can form a gap with the inner wall of the first groove 112.

[0089] A part of the liquid injection barrier layer 20 is wrapped on the surrounding edge 1112, and another part of the liquid injection barrier layer 20 is attached to the inner wall of the liquid injection hole 1111. Among them, the part of the liquid injection barrier layer 20 wrapped on the surrounding edge 1112 is adapted to the shape of the surrounding edge 1112, so that the liquid injection barrier layer 20 can be stably fixed on the shell 10 and is not easy to fall off or displace. At the same time, the liquid injection barrier layer 20 is also attached to the inner wall of the liquid injection hole 1111 to block the liquid injection hole 1111 and the electrolyte. Compared with the way that the barrier layer falls flat on the surface of the shell 10, in the battery monomer 100 provided by the embodiment of the application, the surrounding edge 1112 arranged outside the liquid injection hole 1111 can wrap and fix the liquid injection barrier layer 20, so that the liquid injection barrier layer 20 can be stably attached to the shell 11. Not only can it isolate the electrolyte and the shell 10, but also can reduce the risk of electrolyte flowing into the liquid injection barrier layer 20 below, and reduce the risk of the liquid injection barrier layer 20 falling off or displacing, thereby reducing the risk of electrolyte polluting the shell 10.

[0090] In the battery monomer 100 provided by the embodiment of the present application, the shell 10 comprises an end cover 11, the end cover 11 comprises a first groove 112 and a liquid injection hole structure 111 arranged in the first groove 112, the liquid injection hole structure 111 comprises a liquid injection hole 1111 and a surrounding edge 1112 arranged around the liquid injection hole 1111, the outer edge size of the first groove 112 is greater than the outer edge size of the surrounding edge 1112, in this way, a gap is arranged between the surrounding edge 1112 and the outer edge of the first groove 112, when liquid injection, the liquid injection barrier layer 20 can be wrapped on the surrounding edge 1112, so that the liquid injection barrier layer 20 can isolate the electrolyte from the shell 10, after the electrolyte drops, it can fall on the liquid injection barrier layer 20 and will not directly drop on the shell 10, the above-mentioned battery monomer 100 can reduce the risk that the electrolyte drops on the surface of the shell 10 in the liquid injection process, that is, the risk of electrolyte pollution is reduced, and then the problem that the sealing nail welding efficiency and welding quality are affected due to electrode liquid pollution is improved; at the same time, the liquid injection barrier layer 20 can be stably wrapped on the surrounding edge 1112 and is not easy to fall off or displace, and under the liquid injection pressure, the electrolyte is also not easy to flow into the gap between the liquid injection barrier layer 20 and the inner wall of the liquid injection hole 1111, further reducing the risk of electrolyte pollution.

[0091] In some embodiments, the liquid injection barrier layer 20 is a heat shrinkable film.

[0092] The heat shrinkable film is also called heat shrinkable film, which is a film that can shrink and tightly wrap the product when heated. This film is mainly designed based on the principle of high molecular chain stretching orientation. Its physical principle is that when the polymer is in a high elastic state, it is stretched and oriented. When the polymer is suddenly cooled below the glass transition temperature, the molecular orientation is frozen. At this time, the product is packaged. Due to the stress relaxation of molecular motion, the molecules will return to their original state, resulting in shrinkage.

[0093] The heat shrinkable film can be POF heat shrinkable film, PVC heat shrinkable film, PET heat shrinkable film, PE heat shrinkable film, OPS heat shrinkable film, PVDC heat shrinkable film, etc. The heat shrinkable film has the characteristics of high flexibility, not easy to break, strong anti-explosion force, strong anti-impact function, strong anti-puncture and tear function, strong tension and large shrinkage rate.

[0094] In this way, the liquid injection barrier layer 20 can tightly wrap the shell 10 by heat shrinkage, further improving the protection effect of the shell 10. In other embodiments, the liquid injection barrier layer 20 can also be other types of film layers as long as it can be attached to the liquid injection hole structure 111.

[0095] Please refer to FIGS. 5A to 6, in some embodiments, the liquid injection hole 1111 comprises a through-hole part 1111a and a liquid inlet part 1111b connected in communication, the hole diameter of the through-hole part 1111a is greater than the hole diameter of the liquid inlet part 1111b, the liquid inlet part 1111b penetrates the end cover 11, and the surrounding edge 1112 surrounds the through-hole part 1111a.

[0096] The hole diameter of the counterbore portion 1111a is greater than the hole diameter of the liquid inlet portion 1111b, so that the liquid injection hole 1111 is a stepped hole. The counterbore portion 1111a is used to position the liquid injection nozzle 300, and the liquid inlet portion 1111b is used to allow the electrolyte to flow into the interior of the shell 10. The liquid injection barrier layer 20 is wrapped on the surrounding edge 1112, and the liquid injection barrier layer 20 is attached to the inner wall of the counterbore portion 1111a and the inner wall of the liquid inlet portion 1111b, wherein the inner wall of the counterbore portion 1111a includes the side wall and the bottom wall of the counterbore portion 1111a, so that the liquid injection barrier layer 20 can have a comprehensive barrier protection effect on the liquid injection hole 1111, thereby reducing the risk of electrolyte contamination.

[0097] By adopting the above technical solution, the counterbore portion 1111a can position the liquid injection nozzle 300 and the liquid inlet portion 1111b is used for liquid injection. The surrounding edge 1112 surrounds the counterbore portion 1111a, so that the liquid injection barrier layer 20 wrapped on the surrounding edge 1112 can have a comprehensive barrier protection effect on the liquid injection hole 1111, thereby reducing the risk of electrolyte contamination.

[0098] Please refer to FIGS. 5A to 6. In some embodiments, the surrounding edge 1112 includes a first outer surface 1112a and a first inner surface 1112b oppositely arranged, and a first top surface 1112c connected between the first outer surface 1112a and the first inner surface 1112b. The first inner surface 1112b is the side wall of the counterbore portion 1111a, and the first outer surface 1112a and the first inner surface 1112b are respectively perpendicular to the first top surface 1112c.

[0099] The liquid injection barrier layer 20 is attached to the first outer surface 1112a, the first top surface 1112c, and the first inner surface 1112b.

[0100] The first outer surface 1112a is perpendicular to the first top surface 1112c, which provides a slope foot for the liquid injection barrier layer 20. The first inner surface 1112b is also perpendicular to the first top surface 1112c, which provides a slope foot for the liquid injection barrier layer 20. In this way, the liquid injection barrier layer 20 can be folded twice on the surrounding edge 1112 and form two 90-degree folding angles. The liquid injection barrier layer 20 can be stably wrapped on the surrounding edge 1112 and is not easy to fall off or shift. The shape of the liquid injection barrier layer 20 is adapted to the shape of the surrounding edge 1112 and the liquid injection hole 1111. One end of the liquid injection barrier layer 20 is wrapped on the surrounding edge 1112 and the other end is attached to the inner wall of the liquid injection hole 1111.

[0101] In other embodiments, the first outer surface 1112a and the first top surface 1112c can form an included angle of other angles, and / or the first inner surface 1112b and the first top surface 1112c can form an included angle of other angles.

[0102] In some embodiments, to improve the stability of the liquid injection barrier layer 20, the surface of the surrounding edge 1112 can be further provided with protrusions, recesses or other structures to increase the friction of the surface of the surrounding edge 1112.

[0103] As shown in FIGS. 5A and 5C, in some embodiments, the first top surface 1112c is flush with the outer surface of the end cover 11.

[0104] The outer surface of the end cover 11 refers to the surface of the end cover 11 facing away from the inside of the shell 10. The first top surface 1112c of the surrounding edge 1112 is parallel and flush with the outer surface of the end cover 11. When the end cover 11 is manufactured, only the liquid injection hole 1111 and the first groove 112 need to be manufactured, and the surrounding edge 1112 can be formed between the first groove 112 and the liquid injection hole 1111 without the need for additional manufacturing of the surrounding edge 1112. The shell 10 is simple to manufacture and has a low cost.

[0105] In other embodiments, the first top surface 1112c can also be higher than the outer surface of the end cover 11, or the first top surface 1112c can be lower than the outer surface of the end cover 11.

[0106] Referring to FIG. 5A, in some embodiments, the surrounding edge 1112 is in the shape of a circular ring, and an annular gap is formed between the surrounding edge 1112 and the inner wall of the first groove 112.

[0107] The surrounding edge 1112 is in the shape of a circular ring, and an annular gap is formed between the surrounding edge 1112 and the inner wall of the first groove 112. By providing the gap, the liquid injection barrier layer 20 can be conveniently wrapped on the first outer surface 1112a of the surrounding edge 1112, and the wrapping stability of the liquid injection barrier layer 20 is improved.

[0108] In some embodiments, the first groove 112 is circular, and the liquid injection hole structure 111 is concentrically arranged with the first groove 112. In other embodiments, the first groove 112 and the liquid injection hole structure 111 can also be arranged non-concentrically. In addition, the first groove 112 can also be square or other shapes, as long as the gap can be formed.

[0109] Referring to FIGS. 3, 5A to 7, the embodiments of the second aspect of the present application propose a manufacturing method of a battery monomer 100, comprising:

[0110] Step S1: placing an electrode assembly in the shell 10.

[0111] The shell 10 comprises an end cover 11, the end cover 11 comprises a first groove 112 and a liquid injection hole structure 111 arranged in the first groove 112, the liquid injection hole structure 111 comprises a liquid injection hole 1111 and a surrounding edge 1112 arranged around the liquid injection hole 1111, and the outer edge size of the first groove 112 is greater than the outer edge size of the surrounding edge 1112.

[0112] Optionally, the shell 10 comprises an end cover 11 and a shell body 12, the electrode assembly is first placed in the shell body 12, and then the end cover 11 is covered on the shell body 12.

[0113] In other embodiments, the end cover 11 can also be a side wall of the shell body 12.

[0114] Step S2: coating the injection liquid barrier layer 20, so that the injection liquid barrier layer 20 is coated on the surrounding edge 1112 and adheres to the inner wall of the injection hole 1111.

[0115] Please refer to FIGS. 6-8C, the injection liquid barrier layer 20 is used to isolate the electrolyte and the hole wall of the injection hole 1111 during the injection process, thereby reducing the risk of electrolyte contamination. The injection liquid barrier layer 20 can be a flexible film, such as a heat shrinkable film, or a hard sheet layer, such as a plastic sheet.

[0116] A part of the injection liquid barrier layer 20 is coated on the surrounding edge 1112, and another part of the injection liquid barrier layer 20 adheres to the inner wall of the injection hole 1111. Among them, the part of the injection liquid barrier layer 20 coated on the surrounding edge 1112 is adapted to the shape of the surrounding edge 1112, and the injection liquid barrier layer 20 is arranged by bending on the surrounding edge 1112, so that the injection liquid barrier layer 20 can be stably fixed on the shell 10 and is not easy to fall off or displace; at the same time, the injection liquid barrier layer 20 also adheres to the inner wall of the injection hole 1111 to block the injection hole 1111 and the electrolyte. Compared with the way that the injection liquid barrier layer 20 falls flat on the surface of the shell 10, the injection liquid barrier layer 20 provided in the embodiments of the application can reduce the risk of electrolyte flowing into the lower part of the injection liquid barrier layer 20, and reduce the risk of the injection liquid barrier layer 20 falling off or displacing, thereby reducing the risk of electrolyte contaminating the shell 10.

[0117] Step S3: injecting the electrolyte into the shell 10 through the injection hole 1111.

[0118] Please refer to FIGS. 4 and 5A, during the injection, the injection nozzle 300 is inserted into the injection hole 1111, the injection nozzle 300 injects the electrolyte into the shell 10 through the injection hole 1111, and the injection liquid barrier layer 20 can block the electrolyte from the inner wall of the injection hole 1111, so that the electrolyte is not easy to contact the shell 10; after the injection is completed, the injection nozzle 300 is lifted, and the electrolyte dripping from the injection nozzle 300 will fall on the injection liquid barrier layer 20, so the electrolyte is not easy to contact the shell 10, thereby effectively reducing the problem of electrolyte contaminating the shell 10.

[0119] The manufacturing method of the battery cell 100 provided by the embodiments of the present application includes the following steps: forming a liquid injection hole 1111, a surrounding edge 1112 surrounding the liquid injection hole 1111, and a first groove 112 on the shell 10 of the battery cell 100; the outer edge size of the first groove 112 is greater than the outer edge size of the surrounding edge 1112, i.e., a gap can be formed between the surrounding edge 1112 and the side wall of the first groove 112, so that the liquid injection barrier layer 20 can be conveniently wrapped on the surrounding edge 1112 and attached to the inner wall of the liquid injection hole 1111, i.e., the liquid injection hole 1111 can be wrapped by the liquid injection barrier layer 20, and the liquid injection barrier layer 20 can block the pollution of the electrolyte.

[0120] In the manufacturing method of the battery cell 100, the liquid injection barrier layer 20 is wrapped on the surrounding edge 1112 and attached to the inner wall of the liquid injection hole 1111, so that the liquid injection barrier layer 20 can effectively protect the liquid injection hole 1111. During the liquid injection, the electrolyte is not easy to be sprayed out from between the liquid injection hole 1111 and the liquid injection barrier layer 20, and after the liquid injection is completed, the electrolyte is also not easy to drop around the liquid injection hole 1111. In addition, since the liquid injection barrier layer 20 is wrapped on the surrounding edge 1112, even if the pressure of the injected electrolyte is large, the liquid injection barrier layer 20 is not easy to fall off or shift, and the liquid injection barrier layer 20 can be stably arranged on the liquid injection hole 1111. Therefore, the above manufacturing method can reduce the risk of electrolyte dropping on the shell 10 during the liquid injection process, i.e., the risk of electrolyte pollution is reduced, and the problem of affecting the sealing nail welding efficiency and welding quality due to electrolyte pollution is improved. In addition, the material consumption cost of the above manufacturing method is low, only the liquid injection barrier layer 20 needs to be arranged, the manufacturing difficulty is low, and the production rhythm is not affected, which is a good method for improving electrolyte pollution.

[0121] Please refer to FIGS. 5A to 9C. In some embodiments, the barrier layer 20 is a heat-shrinkable film, and the step S2 of wrapping the liquid injection barrier layer 20 includes the following steps: placing the liquid injection barrier layer 20 on the liquid injection hole structure 111, the liquid injection barrier layer 20 including a liquid injection barrier part 21 and a positioning part 22 arranged at one end of the liquid injection barrier part 21, the liquid injection barrier part 21 being provided with a through hole, and the positioning part 22 extending outward from the edge of the liquid injection barrier part 21, the liquid injection barrier part 21 being arranged in the liquid injection hole 1111 and the positioning part 22 being arranged above the surrounding edge 1112; and performing heat shrinkage treatment on the liquid injection barrier layer 20, so that the positioning part 22 is wrapped on the surrounding edge 1112 and the liquid injection barrier part 21 is attached to the inner wall of the liquid injection hole 1111.

[0122] The liquid injection barrier layer 20 is a heat-shrinkable film, and FIGS. 9A to 9C show the structure of the liquid injection barrier layer 20 before heat shrinkage, and FIGS. 8A to 8D show the structure of the liquid injection barrier layer 20 after heat shrinkage.

[0123] The heat shrinkable film is also called heat shrinkable film, which is a film that shrinks and tightly covers the product when heated. The film is mainly designed based on the principle of high molecular chain stretching orientation. The physical principle is that when the polymer is in a high elastic state, it is stretched and oriented. When the polymer is suddenly cooled below the glass transition temperature, the molecular orientation is frozen. At this time, the product is packaged. Due to the stress relaxation of molecular motion, the molecules will return to their original state, resulting in shrinkage.

[0124] The heat shrinkable film can be POF heat shrinkable film, PVC heat shrinkable film, PET heat shrinkable film, PE heat shrinkable film, OPS heat shrinkable film, PVDC heat shrinkable film, etc. The heat shrinkable film has high flexibility, is not easy to break, has strong anti-explosion force, strong anti-impact function, strong anti-puncture and tear function, strong tension and large shrinkage rate.

[0125] The liquid injection hole 1111 includes a counterbore part 1111a and a liquid injection part 1111b. Before heat shrinking, the liquid injection barrier layer 20 includes a liquid injection barrier part 21 and a positioning part 22 located at one end of the liquid injection barrier part 21. The liquid injection barrier part 21 and the positioning part 22 are integrally arranged. The positioning part 22 is used to fix the liquid injection barrier layer 20 on the shell 10. A through hole is arranged in the liquid injection barrier part 21, and the size of the through hole is matched with the size of the liquid injection part 1111b. Optionally, the diameter of the through hole is equal to the diameter of the liquid injection part 1111b, so as to avoid reducing the liquid injection efficiency and facilitate the adhesion of the liquid injection barrier part 21 to the inner wall of the liquid injection part 1111b. It can be understood that the diameter of the through hole can be slightly larger or slightly smaller than the diameter of the liquid injection part 1111b.

[0126] In some embodiments, before heat shrinking the liquid injection barrier layer 20, the liquid injection barrier layer 20 is a hollow T-shaped film. The liquid injection barrier part 21 is substantially cylindrical, and the positioning part 22 is substantially annular.

[0127] After the liquid injection barrier layer 20 is placed on the liquid injection hole 1111, the liquid injection barrier layer 20 is heat shrunk. The liquid injection barrier layer 20 can be shaped to tightly fit the shape of the shell 10 and tightly cover the shell 10, i.e. the positioning part 22 tightly wraps the surrounding edge 1112, and the liquid injection barrier part 21 tightly adheres to the inner wall of the liquid injection part 1111b. The heat shrinking of the liquid injection barrier layer 20 can be performed in various ways, such as baking, hot air heating, etc.

[0128] By adopting the above technical solution, the liquid injection barrier layer 20 is a heat shrinkable film. The liquid injection barrier layer 20 can be shaped by heat shrinking, so that the positioning part 22 tightly wraps the surrounding edge 1112 and the liquid injection barrier part 21 tightly adheres to the inner wall of the liquid injection hole 1111. During the liquid injection process, the electrolyte is less likely to flow between the liquid injection barrier layer 20 and the liquid injection hole 1111, further improving the barrier protection effect and further reducing the risk of electrolyte contamination.

[0129] Please refer to FIGS. 11-12C. In some embodiments, the step S2 of performing thermal shrinking treatment on the liquid injection barrier layer 20 includes: pressing the hot press head 30 on the liquid injection barrier layer 20 and the liquid injection hole structure 111 to deform the liquid injection barrier layer 20; and heating the liquid injection barrier layer 20 by using the hot press head 30 to perform thermal shrinking treatment on the liquid injection barrier layer 20.

[0130] The hot press head 30 is a component used in the hot press process, which processes and changes the shape and properties of objects by applying high temperature and high pressure. After pressing the hot press head 30 on the liquid injection barrier layer 20, the hot press head 30 is pressed on the surrounding edge 1112 and the counterbore part 1111a at the same time. In this way, the hot press head 30 can deform the liquid injection barrier layer 20 by applying pressure to the liquid injection barrier layer 20 to fit the shape of the shell 10. Then, the hot press head 30 heats the liquid injection barrier layer 20 so that the liquid injection barrier layer 20 shrinks due to heat and tightly wraps around the surrounding edge 1112 and the liquid injection hole 1111.

[0131] By using the above technical solution, the hot press head 30 can deform and shrink the liquid injection barrier layer 20 by applying pressure and heating. The efficiency of the thermal shrinking treatment is high and the thermal shrinking effect is good.

[0132] Please refer to FIGS. 6A-7. In some embodiments, the liquid injection hole 1111 includes a counterbore part 1111a and a liquid inlet part 1111b connected to each other. The hole diameter of the counterbore part 1111a is greater than the hole diameter of the liquid inlet part 1111b.

[0133] The hole diameter of the counterbore part 1111a is greater than the hole diameter of the liquid inlet part 1111b, so that the liquid injection hole 1111 is a stepped hole. The counterbore part 1111a is used to position the liquid injection nozzle 300, and the liquid inlet part 1111b is used to allow the electrolyte to flow into the interior of the shell 10. The liquid injection barrier layer 20 wraps around the surrounding edge 1112, and the liquid injection barrier layer 20 fits the inner wall of the counterbore part 1111a and the inner wall of the liquid inlet part 1111b. The inner wall of the counterbore part 1111a includes the side wall and the bottom wall of the counterbore part 1111a. In this way, the liquid injection barrier layer 20 can provide comprehensive barrier protection for the liquid injection hole 1111, reducing the risk of electrolyte contamination.

[0134] In other embodiments, the liquid injection hole 1111 can also have other structures. For example, the counterbore part 1111a can be omitted. In this case, the liquid injection barrier layer 20 can still fit the inner wall of the liquid injection hole 1111 to provide barrier protection.

[0135] Please refer to FIG. 6A, FIG. 7, FIG. 11 to FIG. 12C, in some embodiments, the hot-pressing head 30 comprises a hot-pressing body 31 and an extension rod 32, one end of the hot-pressing body 31 is provided with a shaped recess 311 surrounding a shaped platform 312, and the extension rod 32 is protruded on the shaped platform 312; when the hot-pressing head 30 is pressed on the liquid injection barrier layer 20 and the liquid injection hole structure 111, the shaped recess 311 accommodates the surrounding edge 1112, the shaped platform 312 is pressed on the blind hole part 1111a, and the extension rod 32 extends into the liquid inlet part 1111b.

[0136] The shape of the hot-pressing body 31 is cylindrical, but is not limited thereto, one end of the hot-pressing body 31 is provided with the shaped recess 311 and the shaped platform 312, the shaped platform 312 is protruded relative to the bottom of the shaped recess 311, and the extension rod 32 extends outward from the surface of the shaped platform 312. When the hot-pressing head 30 is pressed on the liquid injection barrier layer 20, the hot-pressing body 31 is pressed on the positioning part 22 and the extension rod 32 extends into the liquid inlet part 1111b, the positioning part 22 is pressed and deformed, in addition, the top end part of the liquid injection barrier part 21 connected to the positioning part 22 can also be pressed and deformed by the hot-pressing body 31 to fit the inner wall of the blind hole part 1111a.

[0137] The shaped recess 311 is a recess between the outer side wall of the hot-pressing body 31 and the shaped platform 312. Optionally, the surrounding edge 1112 is circular, the shaped recess 311 is also a circular groove, the shaped recess 311 is matched with the surrounding edge 1112, so that the shaped recess 311 and the surrounding edge 1112 can be embedded with each other.

[0138] The blind hole part 1111a is a circular blind groove, the shaped platform 312 is also a circular protrusion, the shaped platform 312 is matched with the blind hole part 1111a, so that the shaped platform 312 and the blind hole part 1111a can be embedded with each other. Optionally, the width of the shaped recess 311 is equal to the width of the surrounding edge 1112, and the diameter of the shaped platform 312 is equal to the diameter of the blind hole part 1111a. It can be understood that, in order to facilitate the hot-pressing body 31 to be pressed on the shell 10, the size of the shaped recess 311 and the size of the surrounding edge 1112 can also have a certain difference, and the size of the shaped platform 312 and the size of the blind hole part 1111a can also have a certain difference.

[0139] By adopting the above technical scheme, one end of the hot-pressing body 31 towards the extension rod 32 is shaped with the liquid injection hole 1111 and the surrounding edge 1112 of the shell 10, and when the hot-pressing body 31 is pressed on the liquid injection barrier layer 20 and the shell 10, the liquid injection barrier layer 20 can be deformed to fit the shape of the surrounding edge 1112 and the liquid injection hole 1111.

[0140] In some embodiments, a plurality of air blowing holes 313 are arranged on the hot-pressing body 31, and the plurality of air blowing holes 313 are distributed on the shaped recess 311 and the shaped platform 312.

[0141] The hot pressing body 31 is provided with a blowing channel (not shown in the figure), and a plurality of blowing holes 313 are in communication with the blowing channel. The hot pressing body 31 blows hot air towards the liquid injection barrier layer 20 through the blowing holes 313. In this way, the hot pressing body 31 performs heat shrinkage treatment on the liquid injection barrier layer 20 by blowing. The blowing heat shrinkage process can realize rapid and efficient shrinkage operation. By controlling the pressure and flow of the gas, heat can be quickly and uniformly transferred to the liquid injection barrier layer 20, thereby quickly achieving the shrinkage effect. The blowing heat shrinkage process can also improve the uniformity of shrinkage. Since the gas can uniformly cover the surface of the liquid injection barrier layer 20, the heat distribution is also more uniform, avoiding the problem of poor heat shrinkage uniformity caused by local overheating. In addition, the blowing heat shrinkage process has good flexibility and can be applied to objects of various shapes and sizes.

[0142] The plurality of blowing holes 313 are distributed on the forming groove 311 and the forming table 312. The plurality of blowing holes 313 can be uniformly distributed to improve the uniformity of heat shrinkage. It can be understood that the blowing holes 313 can also be randomly distributed or adopt other distribution methods. In some embodiments, the plurality of blowing holes 313 are distributed on the groove bottom of the forming groove 311, the side surface of the forming table 312, and the top surface. In this way, the blowing holes 313 can uniformly heat shrink the positioning part 22 of the liquid injection barrier layer 20 and wrap it around the surrounding edge 1112 and the counterbore part 1111a. At the same time, the extension rod 32 is not provided with blowing holes 313. The extension rod 32 is used to press the liquid injection barrier layer 20 (i.e., the liquid injection barrier part 21) in the liquid inlet part 1111b during the heat shrinkage process, so that the liquid injection barrier part 21 tightly adheres to the inner wall of the liquid inlet part 1111b, avoiding the liquid injection barrier part 21 from being warped, and the extension rod 32 does not need to heat shrink the liquid injection barrier part 21.

[0143] By adopting the above technical solution, the hot pressing body 31 performs heat shrinkage treatment on the liquid injection barrier layer 20 by the blowing heat shrinkage process, which can realize rapid and efficient shrinkage operation and improve the uniformity of shrinkage of the liquid injection barrier layer 20, so that the liquid injection barrier layer 20 can tightly adhere to the surrounding edge 1112 and the counterbore part 1111a.

[0144] In some embodiments, the blowing holes 313 are at least one of a circle, an ellipse, and a polygon.

[0145] As shown in FIG. 11, the blowing holes 313 can be circular, and the plurality of blowing holes 313 have the same hole diameter to improve the uniformity of heat shrinkage. It can be understood that the hole diameters of the plurality of blowing holes 313 can also be flexibly set. For example, the hole diameters of the blowing holes 313 in the forming groove 311 are greater than the hole diameters of the blowing holes 313 on the forming table 312, so as to improve the connection strength of the liquid injection barrier layer 20 on the surrounding edge 1112.

[0146] The air inlet 313 can also be elliptical, polygonal or other shapes, including polygons such as triangles, squares, pentagons, hexagons, etc.

[0147] By adopting the above technical solution, the shape of the air blowing hole 313 can be flexibly set to meet the liquid injection requirements. In addition, the size of the air blowing hole 313, the gap between adjacent air blowing holes 313, or the density of the air blowing holes 313 can also be flexibly set to meet the needs of the shrinkage compactness of the liquid injection barrier layer 20 and the production cycle.

[0148] Referring to Figures 6A, 13 to 14B, in some embodiments, after injecting electrolyte into the housing 10, the manufacturing method further includes: laser-cutting the liquid injection barrier layer 20 and removing the liquid injection barrier layer 20.

[0149] By laser-cutting the injection barrier layer 20, the binding force of the injection barrier layer 20 on the housing 10 can be reduced; after laser-cutting the injection barrier layer 20, it can be removed. It can be understood that after removing the injection barrier layer 20, a sealing pin can be welded into the injection hole 1111 to seal the injection hole 1111.

[0150] By adopting the above technical solution, the binding force of the liquid injection barrier layer 20 on the housing 10 can be reduced by laser cutting, making it easier to remove the liquid injection barrier layer 20, so that the liquid injection barrier layer 20 will not hinder the subsequent welding of the sealing nail.

[0151] In some embodiments, cutting and removing the injection barrier layer 20 by laser cutting includes: cutting the injection barrier layer 20 along the perimeter 1112 to divide the injection barrier layer 20 into a first membrane 23a and a second membrane 23b; and removing the first membrane 23a and the second membrane 23b by a vacuum adsorption device.

[0152] Figure 13 illustrates the laser cutting line 23, which extends along the first top surface 1112c of the perimeter 1112 and is annular. The liquid injection barrier layer 20 is divided into a first film 23a and a second film 23b. The first film 23a is the portion of the liquid injection barrier layer 20 that covers the first outer surface 1112a and part of the first top surface 1112c, and the second film 23b is the remaining portion of the liquid injection barrier layer 20.

[0153] In other embodiments, the laser cutting line 23 may also be located in other positions, for example, the laser cutting line 23 may extend along the first outer surface 1112a or the first inner surface 1112b of the perimeter 1112, or extend along the countersunk hole portion 1111a.

[0154] By adopting the above technical solution, the removal step of the liquid injection barrier layer 20 is highly automated, which improves the efficiency of the liquid injection process.

[0155] Please refer to FIG. 3 to FIG. 14B, some embodiments of the present application provide a manufacturing method of a battery cell 100, comprising: placing an electrode assembly into a shell 10, the shell 10 comprising an end cover 11, the end cover 11 comprising a first groove 112 and a liquid injection hole structure 111 arranged in the first groove 112, the liquid injection hole structure 111 comprising a liquid injection hole 1111 and a surrounding edge 1112 arranged around the liquid injection hole 1111, the outer edge size of the first groove 112 being greater than the outer edge size of the surrounding edge 1112; placing a liquid injection barrier layer 20 on the liquid injection hole structure 111, and performing heat shrinkage treatment on the liquid injection barrier layer 20 to make the liquid injection barrier layer 20 wrap on the surrounding edge 1112 and make the liquid injection barrier layer 20 adhere to the inner wall of the liquid injection hole 1111; and injecting electrolyte into the shell 10 through the liquid injection hole 1111. The manufacturing method provided by the embodiments of the present application can improve the problem of electrolyte pollution during the liquid injection process.

[0156] Please refer to FIG. 5A to FIG. 6, FIG. 11 to FIG. 12C, the embodiments of the third aspect of the present application provide a battery cell manufacturing equipment, comprising a hot press head 30, the hot press head 30 is used for wrapping the liquid injection barrier layer 20 on the shell 10 of the battery cell 100.

[0157] The battery cell manufacturing equipment provided by the embodiments of the present application can be used to manufacture the battery cell 100 provided by the first aspect, and / or applied to the manufacturing method of the battery cell 100 provided by the second aspect.

[0158] The battery cell manufacturing equipment provided by the embodiments of the present application comprises a hot press head 30, which can wrap the liquid injection barrier layer 20 on the shell 10 of the battery cell 100, that is, the hot press head 30 can make the liquid injection barrier layer 20 stably wrap on the liquid injection hole structure 111. During the liquid injection process, the liquid injection barrier layer 20 can isolate the electrolyte from the shell 10, and the electrolyte dropped from the liquid injection nozzle 300 can fall on the liquid injection barrier layer without directly falling on the shell, thereby reducing the risk of electrolyte pollution of the shell 10. The battery cell manufacturing equipment provided by the embodiments of the present application can wrap the liquid injection barrier layer 20 on the shell 10 of the battery cell 100 through the hot press head 30. Compared with some existing situations, the liquid injection barrier layer 20 is not easy to displace or fall off, and the risk of electrolyte pollution is further reduced by the battery cell manufacturing equipment provided by the embodiments of the present application.

[0159] In some embodiments, the hot press head 30 comprises a hot press body 31 and an extension rod 32, one end of the hot press body 31 is provided with a shaped table 312 and a shaped groove 311 surrounding the shaped table 312, the extension rod 32 is protruded on the shaped table 312, and the hot press body 31 is used for hot pressing the liquid injection barrier layer 20 to make the liquid injection barrier layer 20 heat shrink and wrap on the shell 10.

[0160] The hot-pressing body 31 is matched with the liquid injection hole structure 111. The hot-pressing body 31 is in a cylindrical shape, but is not limited thereto. The hot-pressing body 31 is provided with a shaped groove 311 and a shaped platform 312 at one end. The shaped platform 312 protrudes relative to the groove bottom of the shaped groove 311. The extension rod 32 extends outward from the surface of the shaped platform 312. The shaped groove 311 can be a groove provided between the outer wall of the hot-pressing body 31 and the shaped platform 312. When the hot-pressing head 30 is pressed against the liquid injection barrier layer 20 and the shell 10, the shaped groove 311 is pressed against the surrounding edge 1112, and the shaped platform 312 is pressed against the counterbore portion 1111a. In this way, the shaped groove 311 and the shaped platform 312 can deform the liquid injection barrier layer 20 to fit the liquid injection hole structure 111, and make the liquid injection barrier layer 20 shrink tightly around the liquid injection hole structure 111, i.e., make the liquid injection barrier layer 20 shrink and wrap around the surrounding edge 1112, and make the liquid injection barrier layer 20 fit the counterbore portion 1111a. The extension rod 32 extends into the liquid inlet portion 1111b. The extension rod 32 can make the part of the liquid injection barrier layer 20 extending into the liquid inlet portion 1111b fit the inner wall of the liquid inlet portion 1111b, so as to avoid the liquid injection barrier layer 20 from being buckled in the liquid inlet portion 1111b.

[0161] When the hot-pressing head 30 is pressed against the liquid injection barrier layer 20 and the shell 10, the shaped groove 311 is pressed against the surrounding edge 1112, and the shaped platform 312 is pressed against the counterbore portion 1111a. In this way, the shaped groove 311 and the shaped platform 312 can deform the liquid injection barrier layer 20 to fit the liquid injection hole structure 111, and make the liquid injection barrier layer 20 shrink tightly around the liquid injection hole structure 111, i.e., make the liquid injection barrier layer 20 shrink and wrap around the surrounding edge 1112, and make the liquid injection barrier layer 20 fit the counterbore portion 1111a. The extension rod 32 extends into the liquid inlet portion 1111b. The extension rod 32 can make the part of the liquid injection barrier layer 20 extending into the liquid inlet portion 1111b fit the inner wall of the liquid inlet portion 1111b, so as to avoid the liquid injection barrier layer 20 from being buckled in the liquid inlet portion 1111b.

[0162] By adopting the technical scheme, the hot-pressing head 30 includes the hot-pressing body 31 and the extension rod 32. The hot-pressing head 30 can deform the liquid injection barrier layer 20 to fit the liquid injection hole structure 111, and make the liquid injection barrier layer 20 shrink tightly around the liquid injection hole structure 111. The extension rod 32 can make the part of the liquid injection barrier layer 20 extending into the liquid inlet portion 1111b fit the inner wall of the liquid inlet portion 1111b, so as to avoid the liquid injection barrier layer 20 from being buckled in the liquid inlet portion 1111b. The hot-pressing head 30 provided by the above embodiment can be used to make the liquid injection barrier layer 20 shrink and wrap around the liquid injection hole structure 111, thereby reducing the problem of pollution of the shell 10 in the electrolyte injection process.

[0163] In some embodiments, the hot-pressing body 31 is provided with a plurality of air blowing holes 313. The plurality of air blowing holes 313 are distributed on the shaped groove 311 and the shaped platform 312 at intervals.

[0164] The hot-pressing body 31 is provided with an air blowing channel. The plurality of air blowing holes 313 are in communication with the air blowing channel. The hot-pressing body 31 blows hot air toward the liquid injection barrier layer 20 through the air blowing holes 313. The air blowing holes 313 are at least one of a circular shape, an elliptical shape, and a polygonal shape.

[0165] The hot-pressing body 31 performs heat shrinkage treatment on the liquid injection barrier layer 20 by blowing, and the blowing heat shrinkage process can realize rapid and efficient shrinkage operation. By controlling the pressure and flow of the gas, heat can be quickly and uniformly transferred to the liquid injection barrier layer 20, thereby quickly realizing the shrinkage effect. The blowing heat shrinkage process can also improve the uniformity of shrinkage. Since the gas can uniformly cover the surface of the liquid injection barrier layer 20, the heat distribution is also more uniform, avoiding the problem of poor heat shrinkage uniformity caused by local overheating. In addition, the blowing heat shrinkage process has good flexibility and can be applied to objects of various shapes and sizes.

[0166] By adopting the above technical solution, the hot-pressing body 31 performs heat shrinkage treatment on the liquid injection barrier layer 20 by blowing heat shrinkage process, which can realize rapid and efficient shrinkage operation and improve the uniformity of shrinkage of the liquid injection barrier layer 20.

[0167] In some embodiments, the shaped groove 311 is a circular ring-shaped groove.

[0168] When the hot-pressing head 30 is pressed on the shell 10, the shaped groove 311 is pressed on the surrounding edge 1112, and the surrounding edge 1112 and the shaped groove 311 are both circular ring-shaped. The shaped groove 311 is adapted in size to the surrounding edge 1112, so that the inner wall of the shaped groove 311 can be attached to the liquid injection barrier layer 20 and the surrounding edge 1112, so that the liquid injection barrier layer 20 is tightly attached to the circumferential side of the surrounding edge 1112.

[0169] By adopting the above technical solution, the shaped groove 311 can cover the liquid injection barrier layer 20 on the circumferential side of the surrounding edge 1112, improving the coverage integrity of the liquid injection barrier layer 20, and the liquid injection barrier layer 20 can isolate the pollution of the electrolyte along the circumferential direction of the liquid injection hole 1111.

[0170] The embodiments of the fourth aspect of the application provide a battery 1 comprising the battery monomer 100 provided by the first aspect or the battery monomer 100 manufactured by the manufacturing method provided by the second aspect.

[0171] The embodiments of the fifth aspect of the application provide a power consumption device comprising the battery 1 provided by the fourth aspect, which is used to provide electric energy.

[0172] The power consumption device can be a device or system using any of the foregoing application batteries.

[0173] The above examples are only used to illustrate the technical solutions of the present application, but not limit the same; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalent ones; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A battery cell, wherein, The battery cell includes: The housing includes an end cap, the end cap including a first groove and an injection hole structure disposed in the first groove, the injection hole structure including an injection hole and a surrounding edge disposed around the injection hole, the outer edge dimension of the first groove being larger than the outer edge dimension of the surrounding edge, the surrounding edge being used to cover an injection barrier layer; The electrode assembly is housed within the housing.

2. The battery cell as described in claim 1, wherein, The injection hole includes a countersunk section and an inlet section that are connected to each other. The diameter of the countersunk section is larger than the diameter of the inlet section. The inlet section penetrates the end cap. The surrounding edge surrounds the countersunk section.

3. The battery cell as described in claim 2, wherein, The surrounding edge includes a first outer surface and a first inner surface disposed opposite to each other, and a first top surface connected between the first outer surface and the first inner surface. The first inner surface is the sidewall of the countersunk hole portion, and the first outer surface and the first inner surface are respectively perpendicular to the first top surface.

4. The battery cell as described in claim 3, wherein, The first top surface is flush with the outer surface of the end cap.

5. The battery cell according to any one of claims 1-4, wherein, The surrounding edge is circular, and an annular gap is formed between the surrounding edge and the inner wall of the first groove.

6. A method for manufacturing a single battery cell, wherein, The manufacturing method includes: The electrode assembly is placed inside the housing, which includes an end cap. The end cap includes a first groove and a liquid injection hole structure disposed in the first groove. The liquid injection hole structure includes a liquid injection hole and a surrounding edge disposed around the liquid injection hole. The outer edge dimension of the first groove is larger than the outer edge dimension of the surrounding edge. A liquid injection barrier layer is applied, such that the liquid injection barrier layer covers the perimeter and adheres to the inner wall of the injection hole; Electrolyte is injected into the housing through the injection hole.

7. The manufacturing method as described in claim 6, wherein, The barrier layer is a heat-shrinkable film, and the coating of the liquid injection barrier layer includes: An injection barrier layer is placed on the injection hole structure. The injection barrier layer includes an injection barrier part and a positioning part located at one end of the injection barrier part. The injection barrier part has a through hole, and the positioning part extends outward from the edge of the injection barrier part. The injection barrier part is located inside the injection hole, and the positioning part is located above the surrounding edge. The injection barrier layer is heat-shrinked so that the positioning part covers the surrounding edge and the injection barrier part fits into the inner wall of the injection hole.

8. The manufacturing method as described in claim 7, wherein, The liquid injection barrier layer is subjected to heat shrinking treatment, including: The hot press head is pressed onto the injection barrier layer and the injection hole structure, causing the injection barrier layer to deform. The liquid injection barrier layer is heated using the hot press head to perform heat shrinking treatment on the liquid injection barrier layer.

9. The manufacturing method as described in claim 8, wherein, The injection hole includes a countersunk section and an inlet section that are connected to each other, and the diameter of the countersunk section is larger than the diameter of the inlet section. The hot press head includes a hot press body and an extension rod. One end of the hot press body is provided with a forming platform and a forming groove surrounding the forming platform. The extension rod protrudes from the forming platform. When the hot press head is pressed on the liquid injection barrier layer and the liquid injection hole structure, the forming groove accommodates the surrounding edge, the forming platform presses on the countersunk hole, and the extension rod extends into the liquid inlet.

10. The manufacturing method as described in claim 9, wherein, The hot-pressing body is provided with a plurality of air blowing holes, which are spaced apart on the forming groove and the forming table; The method of heating the liquid injection barrier layer using the hot press head includes: Hot air is blown toward the liquid injection barrier layer through the air blowing hole.

11. The manufacturing method according to any one of claims 6-10, wherein, After injecting electrolyte into the housing, the manufacturing method further includes: The injection barrier layer is cut by laser and then removed.

12. The manufacturing method as described in claim 11, wherein, The process includes laser cutting of the injection barrier layer and removal of the injection barrier layer, comprising: Cut the injection barrier layer along the perimeter to divide the injection barrier layer into a first film and a second film; The first membrane and the second membrane are removed by a vacuum adsorption device.

13. A battery cell manufacturing apparatus, wherein, The battery cell manufacturing equipment includes a hot press head, which is used to coat the liquid injection barrier layer onto the battery cell housing.

14. The battery cell manufacturing equipment as described in claim 13, wherein, The hot press head includes a hot press body and an extension rod. One end of the hot press body is provided with a forming platform and a forming groove surrounding the forming platform. The extension rod protrudes from the forming platform. The hot press body is used to hot press the liquid injection barrier layer so that the liquid injection barrier layer shrinks and covers the housing.

15. The battery cell manufacturing equipment as described in claim 14, wherein, The hot-pressing body is provided with a plurality of air blowing holes, which are spaced apart on the forming groove and the forming table.

16. The battery cell manufacturing equipment as described in claim 14 or 15, wherein, The forming groove is a circular groove.

17. A battery, wherein, The battery comprises a battery cell as described in any one of claims 1-5, or a battery cell manufactured by the method of manufacturing a battery cell as described in any one of claims 6-12.

18. An electrical appliance, wherein, The electrical device includes the battery as described in claim 17, the battery being used to provide electrical energy.

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