End cap assembly, battery, electric device, battery cell and manufacturing method thereof

Abstract

The present application provides an end cap assembly, a battery, an electrical device, a battery cell and a method for manufacturing the same, which are used in the technical field of batteries and energy storage devices. The end cap assembly includes an end cap and an insulating member, and is used for a battery cell. The end cap is provided with an injection hole, and the injection hole is used to inject electrolyte into the interior of the battery cell. The insulating member is provided with a protective assembly on one side of the injection hole along the thickness direction of the end cap close to the interior of the battery cell, and the protective assembly includes an opening and closing mechanism, and the opening and closing mechanism is configured to open when injecting electrolyte into the battery cell and close after the injection of electrolyte into the battery cell is completed. The end cap assembly can reduce the influence of external water vapor on the interior of the battery cell and increase the service life of the battery cell.

Description

Technical Field

[0001] The present application relates to the technical field of batteries and energy storage devices, and in particular to an end cover assembly, a battery, an electrical device, a battery cell and a manufacturing method thereof. Background Art

[0002] Batteries are widely used in electronic devices such as vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys and power tools, etc.

[0003] People have increasingly higher requirements on the performance of batteries that provide energy. If water vapor enters the battery cells during the production process, it will affect the performance of the battery cells. Therefore, how to strictly control the entry of water vapor into the battery cells during the production process has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] The present application provides an end cover assembly, a battery, an electrical device, a battery cell and a manufacturing method thereof, including a protective assembly with an opening and closing mechanism that can delay water vapor from entering the interior of the battery cell.

[0005] According to a first aspect of the present application, there is provided an end cover assembly for a battery cell, comprising: an end cover, the end cover being provided with an injection hole, the injection hole being used to inject electrolyte into the interior of the battery cell; and an insulating member, the insulating member being provided with a protective assembly on one side of the injection hole close to the interior of the battery cell along the thickness direction of the end cover, the protective assembly being arranged opposite to the injection hole, the protective assembly comprising an opening and closing mechanism, the opening and closing mechanism being configured to open when injecting electrolyte into the battery cell to allow electrolyte to enter the interior of the battery cell, and to close after the injection of electrolyte into the battery cell is completed.

[0006] In the embodiment of the present application, the protective component is in an open state when the electrolyte is injected into the battery cell, and remains in a closed state after the electrolyte is injected into the battery cell. This can reduce the contact area between the inside of the battery cell and the outside air, reduce the entry of external water vapor into the battery cell, and increase the service life of the battery cell.

[0007] In some embodiments, the protective component includes a bottom wall and a side wall, and the opening and closing mechanism is arranged on the side wall. By arranging a protective component corresponding to the position of the injection hole on the insulating component, and the protective component includes a bottom wall and a side wall, and the opening and closing mechanism is arranged on the side wall, the electrolyte flows from the side wall of the protective component into the interior of the battery cell under the guidance of the opening and closing mechanism. In this way, the electrolyte will first pass through the buffer of the bottom wall and then enter the interior of the battery cell, instead of directly entering the interior of the battery cell during the injection process, changing the flow direction of the electrolyte, reducing the impact force on the electrode assembly inside the battery cell, reducing the possibility of the electrode assembly being damaged by the impact, and thus improving the service life of the battery cell.

[0008] In some embodiments, the protection assembly includes multiple opening and closing mechanisms, and the multiple opening and closing mechanisms are arranged along the thickness direction of the end cover. The multiple opening and closing mechanisms arranged along the thickness direction of the end cover can increase the flow rate of the electrolyte flowing from the side wall of the protection assembly into the interior of the battery cell, thereby improving the injection efficiency.

[0009] In some embodiments, the protection component includes a plurality of opening and closing mechanisms, and the plurality of opening and closing mechanisms are arranged along the circumference of the injection hole. Arranging a plurality of opening and closing mechanisms along the circumference of the injection hole can further increase the flow rate of electrolyte injection and improve the injection efficiency.

[0010] In some embodiments, the side wall includes a plurality of connection posts, and the plurality of connection posts are arranged at intervals along the circumference of the injection hole. Two adjacent connection posts among the plurality of connection posts are arranged at both ends of the opening and closing mechanism, and the opening and closing mechanism is rotatably connected to the connection posts. The opening and closing mechanism is rotatably connected to the connection posts, and under the action of pressure, the opening and closing mechanism can be automatically opened when liquid is injected into the battery cell, and automatically closed after the liquid injection into the battery cell is completed. The structure is simple, the operation is simple, and it is easy to implement.

[0011] In some embodiments, the connecting column is provided with a connecting hole, the opening and closing mechanism is provided with a connecting shaft, and the connecting shaft is provided in the connecting hole.

[0012] In some embodiments, the connection column is provided with a plurality of connection holes along the thickness direction of the end cap, the protection assembly includes a plurality of opening and closing mechanisms, the plurality of connection holes are provided corresponding to the plurality of opening and closing mechanisms, and the spacing between two adjacent connection holes is greater than the height of the opening and closing mechanism. The spacing between two adjacent connection holes is greater than the height of the opening and closing mechanism, and the opening and closing mechanism will not interfere with the adjacent opening and closing mechanism during movement, which is beneficial to the movement of the opening and closing mechanism, so that the injection process can proceed smoothly.

[0013] In some embodiments, along the thickness direction of the end cap, the central axis of the connecting shaft is located above the central axis of the opening and closing mechanism. When the opening and closing mechanism is flipped open under positive pressure or negative pressure, along the thickness direction of the end cap, the central axis of the connecting shaft is located above the central axis of the opening and closing mechanism. After the opening and closing mechanism is restored to normal pressure, it can be restored to its original state by its own gravity and automatically closed, so that the protective component is in a closed state under normal pressure. The structure is simple and no additional components are required.

[0014] In some embodiments, the distance between two adjacent connecting columns is greater than the length of the opening and closing mechanism along the circumference of the injection hole. When the opening and closing mechanism is opened under positive pressure or negative pressure, the distance between two adjacent connecting columns is greater than the length of the opening and closing mechanism along the circumference of the injection hole, and the opening and closing mechanism will not interfere with the connecting columns during movement, which is beneficial to the movement of the opening and closing mechanism, so that the injection process can proceed smoothly.

[0015] In some embodiments, the thickness of the opening and closing mechanism is between 0.5 mm and 3 mm along the direction of opening and closing of the opening and closing mechanism. The thickness of the opening and closing mechanism is not less than 3 mm, which can make the opening and closing mechanism not easily deformed, and further, can ensure the sealing effect of the opening and closing mechanism when it is closed. The thickness of the opening and closing mechanism is not more than 3 mm, which is conducive to achieving the purpose of automatic opening of the opening and closing mechanism when the electrolyte is injected into the battery cell under the action of pressure.

[0016] In some embodiments, along the thickness direction of the end cap, the projection of the injection hole is located within the projection of the protective component. Along the thickness direction of the end cap, the projection of the injection hole is located within the projection of the protective component, which ensures the relative position of the injection hole and the protective component. When injecting electrolyte into the battery cell, the protective component will not hinder the electrolyte, which facilitates the smooth inflow of the electrolyte and ensures the injection efficiency.

[0017] In some embodiments, the thickness of the bottom wall is not less than the thickness of the side wall. When the electrolyte is injected into the battery cell, the bottom wall of the protective component is first impacted by the electrolyte. The thick bottom wall can effectively resist the impact of the electrolyte and ensure the normal use of the protective component.

[0018] According to a second aspect of the present application, a battery cell is provided, comprising: a shell having an opening; and an end cover assembly according to the first aspect, the end cover assembly being used to cover the opening.

[0019] According to a third aspect of the present application, a battery is provided, comprising: the battery cell of the second aspect; and a box body for accommodating the battery cell.

[0020] According to a fourth aspect of the present application, there is provided an electrical device, comprising: the battery of the third aspect, the battery being used to provide electrical energy.

[0021] According to the fifth aspect of the present application, a manufacturing method of a battery cell is provided, comprising: providing a shell, the shell being provided with an opening; providing an end cap assembly, the end cap assembly comprising: an end cap, the end cap being provided with a liquid injection hole, the liquid injection hole being used to inject electrolyte into the battery cell; and an insulating member, the insulating member being provided with a protective assembly on one side of the liquid injection hole along the thickness direction of the end cap close to the inside of the battery cell, the protective assembly comprising an opening and closing mechanism, the opening and closing mechanism being configured to open when injecting electrolyte into the battery cell, and to close after the electrolyte is injected into the battery cell; and covering the opening with the end cap assembly. The protective assembly can reduce the contact area between the inside of the battery cell and the outside air, reduce the influence of the outside water vapor on the inside of the battery cell, and can increase the service life of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without paying creative work.

[0023] Figure 1 A schematic diagram of the structure of a vehicle according to an embodiment of the present application;

[0024] Figure 2 This is a schematic diagram of the exploded structure of a battery according to an embodiment of the present application;

[0025] Figure 3 A schematic diagram of the structure of a battery cell according to an embodiment of the present application;

[0026] Figure 4 This is a schematic diagram of the exploded structure of a battery cell according to an embodiment of the present application;

[0027] Figure 5 A bottom view of an end cap assembly according to an embodiment of the present application;

[0028] Figure 6 This is a schematic diagram of the structure of a protection component according to an embodiment of the present application;

[0029] Figure 7 This is a schematic cross-sectional structural diagram of a protection component according to an embodiment of the present application;

[0030] Figure 8 A partial structural schematic diagram of a protection component according to an embodiment of the present application;

[0031] Fig. 9 This is a schematic diagram of the structure of an opening and closing mechanism of an embodiment of the present application;

[0032] Fig.10 The present invention is a flowchart of a method for manufacturing a battery cell according to an embodiment of the present invention.

[0033] In the drawings, the drawings are not drawn to scale.

[0034] Marking Description:

[0035] 1-Vehicle; 10-Battery; 11-Controller; 12-Motor;

[0036] 20-box; 21-battery cell; 22-shell; 221-opening; 222-electrode assembly;

[0037] 30-end cap assembly; 31-end cap; 311-liquid injection hole; 32-insulating member; 33-electrode terminal;

[0038] 40-protection assembly; 41-bottom wall; 42-side wall; 421-connecting column; 421a-connecting hole; 422-opening and closing mechanism; 422a-connecting shaft;

[0039] H1-the height of the opening and closing mechanism; H2-the distance between two adjacent connecting holes; W1-the length of the opening and closing mechanism along the circumference of the injection hole; W2-the distance between two adjacent connecting columns. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0041] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0042] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0043] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0044] The term "plurality" used in the present application refers to two or more (including two).

[0045] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack. The battery generally includes a box for accommodating one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0046] In order to meet different power usage requirements, the battery may include a plurality of battery cells, wherein the plurality of battery cells may be connected in series, in parallel, or in hybrid connection, wherein hybrid connection refers to a mixture of series connection and parallel connection.

[0047] In the present 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 the present application do not limit this. Battery cells may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this. Battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application do not limit this.

[0048] The battery cell includes an electrode assembly and an electrolyte. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The current collector not coated with the positive electrode active material layer protrudes from the current collector coated with the positive electrode active material layer. The current collector not coated with the positive electrode active material layer serves as the positive electrode tab. Taking lithium-ion batteries as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The current collector not coated with the negative electrode active material layer protrudes from the current collector coated with the negative electrode active material layer. The current collector not coated with the negative electrode active material layer serves as the negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon, etc. In order to ensure that a large current can pass without melting, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together. The material of the isolation film can be PP (polypropylene) or PE (polyethylene). In addition, the electrode assembly can be a winding structure or a laminated structure, and the embodiments of the present application are not limited thereto.

[0049] After the electrode assembly is put into the battery shell, the electrolyte needs to be poured into the battery cell. However, in the process before welding the sealing nail, the water vapor in the air can easily enter the battery cell, causing corrosion of the electrode and affecting the service life of the battery cell. Therefore, in the process from the electrode assembly into the shell to the welding of the sealing nail, it is usually necessary to use a glue nail to temporarily seal the injection hole and strictly control the temperature and humidity in the air.

[0050] However, after the electrode assembly is baked but before liquid injection, and before the glue nails are installed, water vapor can still easily enter the battery cell. Therefore, how to delay the entry of water vapor into the battery cell becomes a problem that needs to be solved urgently.

[0051] In view of this, the present application proposes a protective component located below the injection hole and including an opening and closing mechanism. The protective component is in an open state when electrolyte is injected into the battery cell, and remains in a closed state after the electrolyte is injected into the battery cell, thereby reducing the contact area between the inside of the battery cell and the outside air and reducing the impact of external water vapor.

[0052] An embodiment of the present application provides an electrical device, wherein a battery is used to provide electrical energy.

[0053] The technical solutions described in the embodiments of the present application are applicable to batteries and various electrical devices using batteries, and the electrical devices may be vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools, etc. The vehicle may be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, etc.; the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.; the electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.; the electric tools may 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.

[0054] It should be understood that the technical solutions described in the embodiments of the present application are not limited to the devices described above, but can also be applied to all devices using batteries. However, for the sake of simplicity, the following embodiments are described using electric vehicles as examples.

[0055] For example, Figure 1As shown, it is a schematic diagram of the structure of a vehicle 1 according to an embodiment of the present application. The vehicle 1 may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 10 may be provided inside the vehicle 1. Specifically, for example, the battery 10 may be provided at the bottom, front or rear of the vehicle 1. The battery 10 may be used to power the vehicle 1. For example, the battery 10 may be used as an operating power source for the vehicle 1. The vehicle 1 may further include a controller 11 and a motor 12. The controller 11 is used, for example, to control the battery 10 to power the motor 12. The battery 10 may be used for the starting, navigation and operating power requirements of the vehicle 1. Of course, the battery 10 may also be used to drive the vehicle 1 to travel, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0056] like Figure 2 As shown, it is a schematic diagram of the exploded structure of a battery 10 according to an embodiment of the present application. The battery 10 includes a battery cell 21 and a case 20, and the case 20 is used to accommodate the battery cell 21. The number of battery cells 21 may be one or more. When there are multiple battery cells 21, multiple battery cells 21 are arranged in the case 20. There are many types of cases 20, and the case 20 may be a frame-shaped case, a disc-shaped case, or a box-shaped case, etc. Specifically, the case 20 may include a lower case for accommodating the battery cell 21 and an upper case covering the lower case. Among them, the covering parts of the upper case and the lower case can be sealed by a sealing element, and the sealing element can be a sealing ring, a sealant, etc.

[0057] Optionally, the battery 10 may also include other structures, which will not be described in detail here, such as a combination of multiple layers of battery cells 21, or a busbar component, a signal collection harness, a processor, etc.

[0058] Figure 3 It is a schematic structural diagram of a battery cell 21 according to an embodiment of the present application. Figure 4 It is a schematic diagram of the exploded structure of a battery cell 21 according to an embodiment of the present application.

[0059] like Figure 4 As shown, the battery cell 21 includes a shell 22 and an end cover assembly 30, the shell 22 is provided with an opening 221, and the end cover assembly 30 is used to cover the opening 221. The shell 22 can be in various shapes, such as a cylinder, a cuboid, etc. The shell 22 can be used to contain an electrolyte, such as an electrolyte. Optionally, an electrode assembly 222 is also provided in the shell 22 of the battery cell 21. The shape of the shell 22 can be determined according to the specific shape of the electrode assembly 222. For example, if the electrode assembly 222 is a cylindrical structure, the shell 22 can be selected as a cylindrical structure; if the electrode assembly 222 is a cuboid structure, the shell 22 can be selected as a cuboid structure. As an example, if Figure 4As shown, the shell 22 is a hollow rectangular parallelepiped structure with one end open, and the open end of the shell 22 forms an opening 221. The shell 22 can be made of metal, such as copper, iron, aluminum, steel, aluminum alloy, etc., and of course, can also be made of non-metallic materials, which is not particularly limited in the present embodiment of the application.

[0060] Optionally, the shell 22 may have one or two openings 221. If the shell 22 has one opening 221, the end cap assembly 30 may also be one. If the shell 22 has two openings 221, for example, the two openings 221 are disposed on opposite sides of the shell 22, the end cap assembly 30 may also be two, and the two end cap assemblies 30 respectively cover the two openings 221 of the shell 22.

[0061] Please also read Figures 5 to 9 , Figure 5 1 is a bottom view of an end cover assembly 30 according to an embodiment of the present application. Figure 6 It is a schematic structural diagram of a protection component 40 according to an embodiment of the present application. Figure 7 It is a schematic cross-sectional structural diagram of a protection component 40 according to an embodiment of the present application. Figure 8 It is a partial structural schematic diagram of a protection component 40 according to an embodiment of the present application. Fig. 9 Schematic diagram of the structure of the opening and closing mechanism 422 according to an embodiment of the present application.

[0062] The present application provides an end cover assembly 30 for a battery cell 21, comprising: an end cover 31, wherein the end cover 31 is provided with an injection hole 311, wherein the injection hole 311 is used to inject electrolyte into the interior of the battery cell 21; and an insulating member 32, wherein the insulating member 32 is provided with a protective member 40 on one side of the injection hole 311 close to the interior of the battery cell 21 along the thickness direction of the end cover 31, wherein the protective member 40 is arranged opposite to the injection hole 311, and wherein the protective member 40 comprises an opening and closing mechanism 422, wherein the opening and closing mechanism 422 is configured to open when injecting electrolyte into the battery cell 21 to allow electrolyte to enter the interior of the battery cell 21, and to close after the injection of electrolyte into the battery cell 21 is completed.

[0063] The end cap assembly 30 is used to cover the opening 221 of the housing 22. The end cap assembly 30 includes an end cap 31, an insulating member 32, a liquid injection hole 311 and an electrode terminal 33. The end cap 31 in the end cap assembly 30 is used to cover the opening 221 of the housing 22. The end cap 31 can be in various shapes, such as circular, rectangular, etc. The shape of the end cap 31 depends on the shape of the housing 22. If the housing 22 is a cylindrical structure, a circular end cap can be selected; if the housing 22 is a rectangular parallelepiped structure, a rectangular end cap can be selected. Figure 4The case where the end cap 31 is rectangular is exemplarily shown. The electrode terminal 33 of the end cap assembly 30 is electrically connected to the electrode assembly 222 in the housing 22. To reduce the risk of short circuit caused by contact between the end cap 31 and the electrode assembly 222, the end cap 31 can be isolated from the housing 22 by an insulating member 32.

[0064] Optionally, there may be two end cap assemblies 30 in the battery cell 21, and the structures of the two end cap assemblies 30 may be the same or different. For example, the end cap 31 of one end cap assembly 30 is provided with a liquid injection hole 311, while the end cap 31 of the other end cap assembly 30 is not provided with a liquid injection hole 311. As an example, Figure 4 As shown, the housing 22 of the battery cell 21 has an opening 221, and the end cover 31 is provided with a liquid injection hole 311. The electrolyte can be injected into the battery cell 21 through the liquid injection hole 311.

[0065] The protective component 40 in the insulating member 32 is located on a side of the injection hole 311 along the thickness direction of the end cover 31 close to the inside of the battery cell 21, wherein the protective component 40 is arranged opposite to the injection hole 311, that is, the projections of the protective component 40 and the injection hole 311 along the thickness direction of the end cover 31 at least partially overlap, so that the electrolyte can enter the protective component 40 from the injection hole 311. Specifically, when injecting liquid into the battery cell 21, the electrolyte first passes through the injection hole 311, and then passes through the protective component 40 to enter the inside of the shell 22. Optionally, the protective component 40 and the insulating member 32 can be an integrally molded structure or a split structure. For example, the protective component 40 and the insulating member 32 are a split structure, and the protective component 40 is connected to the bottom surface of the insulating member 32 on the side close to the inside of the battery cell 21 by bonding, welding, or clamping. The material of the protective component 40 and the insulating member 32 may be the same or different. For example, the material of the insulating member 32 and the protective component 40 may be insulating products such as mica, rubber, resin, plastic, etc., or may be high molecular polymers or nanomaterials.

[0066] The opening and closing mechanism 422 is a mechanism that can open and close. When liquid is injected into the battery cell 21, positive pressure is usually applied during the injection. Under the action of the positive pressure, the opening and closing mechanism 422 opens. After the injection is completed, the inside of the battery cell 21 returns to a normal pressure state, and the opening and closing mechanism 422 closes. Before the sealing nail welding process, the temperature, humidity and other conditions of the external environment of the battery cell 21 need to be strictly controlled. The opening and closing mechanism 422 can reduce the contact area between the inside of the battery cell 21 and the outside world in the closed state, and reduce the possibility of water vapor entering the inside of the battery cell 21. In this way, the requirements for the external environment can be reduced, and the cost of controlling the humidity of the environment can be further reduced. Optionally, elastic sealing materials can be added around the opening and closing mechanism 422 to reduce the gap between the opening and closing mechanism 422 and other components, further improve the sealing effect of the opening and closing mechanism 422 in the closed state, and thus ensure the sealing of the battery cell 21 during transportation. The elastic sealing material can be, for example, plastic, rubber, etc.

[0067] The embodiment of the present application discloses a protective component 40 including an opening and closing mechanism 422. The protective component 40 is in an open state when electrolyte is injected into the battery cell 21, and remains in a closed state after the electrolyte is injected into the battery cell 21. This can reduce the contact area between the inside of the battery cell 21 and the outside air, reduce the entry of external water vapor into the battery cell 21, and increase the service life of the battery cell 21.

[0068] In some embodiments, the protection assembly 40 includes a bottom wall 41 and a side wall 42 , and the opening and closing mechanism 422 is disposed on the side wall 42 .

[0069] Along the thickness direction of the end cover 31, the protective component 40 is arranged on the side of the injection hole 311 close to the inside of the battery cell 21, the bottom wall 41 is arranged toward the injection hole 311, and the side wall 42 is arranged circumferentially along the injection hole 311, and together with the bottom wall 41, it constitutes a accommodating space. Optionally, the bottom wall 41 can be arranged parallel to the end cover 31, or it can be arranged at an angle. When the bottom wall 41 is arranged at an angle, the electrolyte can be guided to the opening and closing mechanism 422 to speed up the flow rate of the electrolyte and improve the injection efficiency. The protective component 40 can be a column, such as a cylinder, a prism, etc. When the electrolyte is poured into the interior of the battery cell 21, specifically, the electrolyte enters the accommodating space of the protective component 40 from the injection hole 311 of the end cover 31, passes through the bottom wall 41, and then enters the interior of the battery cell 21 through the opening and closing mechanism 422 on the side wall 42.

[0070] It is understandable that the above embodiment is described by taking the placement state of the battery cell 21 when the electrolyte is injected as an example, and the battery cell 21 can be placed in other ways in actual application.

[0071] By setting a protective component 40 corresponding to the position of the injection hole 311 on the insulating component 32, and the protective component 40 includes a bottom wall 41 and a side wall 42, and the opening and closing mechanism 422 is set on the side wall 42, so that the electrolyte flows from the side wall 42 of the protective component 40 into the interior of the battery cell 21 under the guidance of the opening and closing mechanism 422. In this way, the electrolyte will first pass through the buffer of the bottom wall 42 and then enter the interior of the battery cell 21, instead of directly entering the interior of the battery cell 21 during the injection process, thereby changing the flow direction of the electrolyte, reducing the impact force on the electrode assembly 222 inside the battery cell 21, reducing the possibility of the electrode assembly 222 being damaged by the impact, and thereby improving the service life of the battery cell 21.

[0072] In some embodiments, the protection assembly 40 includes a plurality of opening and closing mechanisms 422 , and the plurality of opening and closing mechanisms 422 are arranged along the thickness direction of the end cover 31 .

[0073] The plurality of opening and closing mechanisms 422 arranged along the thickness direction of the end cover 31 can increase the flow rate of the electrolyte flowing from the side wall 42 of the protection assembly 40 into the interior of the battery cell 21 , thereby improving the injection efficiency.

[0074] In some embodiments, the protection component 40 includes a plurality of opening and closing mechanisms 422 , and the plurality of opening and closing mechanisms 422 are arranged along the circumference of the injection hole 311 .

[0075] Providing a plurality of opening and closing mechanisms 422 along the circumference of the injection hole 311 can further increase the flow rate of electrolyte injection and improve the injection efficiency.

[0076] In some embodiments, the side wall 42 includes a plurality of connecting columns 421 , which are arranged at intervals along the circumference of the injection hole 311 , and two adjacent connecting columns 421 among the plurality of connecting columns 421 are arranged at both ends of the opening and closing mechanism 422 , and the opening and closing mechanism 422 is rotatably connected to the connecting columns 421 .

[0077] The opening and closing mechanism 422 is connected to the connecting column 421 by rotation. In some embodiments, it can be a clearance fit, such as achieved by relative movement of a sliding bearing, a guide rail and a slider, or it can be a relative rotation. In other embodiments, it can also be an interference fit, such as achieved by a fixed connection between a hub and a shaft. Or, in other embodiments, it can also be a transition fit, such as achieved by a detachable connection between a gear and a shaft, a locating pin and a locating hole. In different structures, different structures can be used for connection, but all can achieve the purpose of rotatably connecting the opening and closing mechanism 422 and the connecting column 421.

[0078] The opening and closing mechanism 422 is rotatably connected to the connecting column 421. Under the action of pressure, the opening and closing mechanism 422 can automatically open when liquid is injected into the battery cell 21, and automatically close after the liquid is injected into the battery cell 21. It has a simple structure, is easy to operate, and is easy to implement.

[0079] In some embodiments, the connecting column 421 is provided with a connecting hole 421 a , and the opening and closing mechanism 422 is provided with a connecting shaft 422 a , and the connecting shaft 422 a is disposed in the connecting hole 421 a .

[0080] like Figure 7 As shown, the connection hole 421a is a blind hole on the connection column 421. The connection shaft 422a is a cylindrical component passing through the middle of the connection hole 421a, and is used to support the rotation of the opening and closing mechanism 422.

[0081] It is understandable that the connecting shaft 422a and the opening and closing mechanism 422 can be an integrally formed structure or a split structure. For example, the connecting shaft 422a and the opening and closing mechanism 422 are split structures, and the connecting shaft 422a is connected to the two ends of the opening and closing mechanism 422 and the connecting hole 421a opposite each other by bonding or welding.

[0082] In some embodiments, along the thickness direction of the end cover 31, the connecting column 421 is provided with a plurality of connecting holes 421a, the protective component 40 includes a plurality of opening and closing mechanisms 422, the plurality of connecting holes 421a are arranged correspondingly to the plurality of opening and closing mechanisms 422, and the distance H2 between two adjacent connecting holes 421a is greater than the height H1 of the opening and closing mechanism 422.

[0083] like Figure 7 As shown, the two adjacent connection holes 421 a here refer to two adjacent connection holes 421 a on the same connection column 421 connected along the thickness direction of the end cover 31 . Figure 7H1 in the figure can be the height of the opening and closing mechanism 422, which is the shortest distance between the connecting shaft 422a along the thickness direction of the end cover 31 and the bottom surface of the other end of the opening and closing mechanism 422 away from the connecting shaft 422a. H2 can be the distance between two adjacent connecting holes 421a, which is the shortest distance between two adjacent connecting holes 421a along the thickness direction of the end cover 31. The distance H2 between two adjacent connecting holes 421a is greater than the height H1 of the opening and closing mechanism 422, which is conducive to the rotation of the opening and closing mechanism 422. When injecting electrolyte into the battery cell 21, it is usually in a positive pressure state, and the opening and closing mechanism 422 can be opened in a direction away from the accommodation space formed by the side wall 42 and the bottom wall 41. Before injecting electrolyte into the battery cell 21, it is usually necessary to first draw negative pressure. In the negative pressure state, the opening and closing mechanism 422 can be opened in a direction close to the vertical central axis of the injection hole 311, and then the electrolyte is injected under positive pressure. When injecting electrolyte, the opening and closing mechanism 422 is opened again in a direction away from the accommodation space formed by the side wall 42 and the bottom wall 41. Therefore, the distance H2 between two adjacent connection holes 421a is greater than the height H1 of the opening and closing mechanism 422, and the opening and closing mechanism 422 will not interfere with the adjacent opening and closing mechanism 422 during movement, which is beneficial to the movement of the opening and closing mechanism 422, so that the injection process can proceed smoothly.

[0084] In some embodiments, along the thickness direction of the end cover 31 , the central axis of the connecting shaft 422 a is located above the central axis of the opening and closing mechanism 422 .

[0085] When the opening and closing mechanism 422 is flipped open under positive pressure or negative pressure, along the thickness direction of the end cover 31, the central axis of the connecting shaft 422a is located above the central axis of the opening and closing mechanism 422. After the opening and closing mechanism 422 is restored to normal pressure, it can return to its original state under its own gravity and close automatically, so that the protective component 40 is in a closed state under normal pressure. The structure is simple and no additional components are required.

[0086] It is understandable that, in some embodiments, a reset structure, such as a spring, etc., may be provided to achieve the reset closure of the opening and closing mechanism 422 .

[0087] In some embodiments, the interval W2 between two adjacent connecting pillars 421 is greater than the length W1 of the opening and closing mechanism 422 along the circumference of the injection hole 311 .

[0088] Figure 7W1 in the figure can be the length of the opening and closing mechanism 422 along the circumference of the injection hole 311, which is the shortest distance between the two ends of the opening and closing mechanism 422 along the circumference of the injection hole 311, and W2 can be the distance between two adjacent connecting pillars 421, which is the shortest distance between two adjacent connecting pillars 421 along the circumference of the injection hole 311. When the opening and closing mechanism 422 is opened under positive pressure or negative pressure, the distance W2 between two adjacent connecting pillars 421 is greater than the length W1 of the opening and closing mechanism 422 along the circumference of the injection hole 311, and the opening and closing mechanism 422 will not interfere with the connecting pillars 421 during movement, which is beneficial to the movement of the opening and closing mechanism 422, so that the injection process can proceed smoothly.

[0089] In some embodiments, the thickness of the opening and closing mechanism 422 is between 0.5 mm and 3 mm along the opening and closing direction of the opening and closing mechanism 422. The thickness of the opening and closing mechanism 422 is not less than 0.5 mm, so that the opening and closing mechanism 422 is not easily deformed, and further, the sealing effect of the opening and closing mechanism 422 when closed can be ensured. The thickness of the opening and closing mechanism 422 is not more than 3 mm, which is conducive to achieving the purpose of automatic opening of the opening and closing mechanism 422 when the electrolyte is injected into the battery cell 21 under the action of pressure.

[0090] In some embodiments, along the thickness direction of the end cover 31 , the projection of the injection hole 311 is located within the projection of the protective component 40 .

[0091] Along the thickness direction of the end cover 31, the projection of the injection hole 311 is located within the projection of the protective component 40, ensuring the relative position of the injection hole 311 and the protective component 40. When the electrolyte is injected into the battery cell 21, the protective component 40 will not cause obstruction to the electrolyte, which facilitates the smooth inflow of the electrolyte and ensures the injection efficiency.

[0092] In some embodiments, the thickness of the bottom wall 41 is not less than the thickness of the side wall 42 .

[0093] When the electrolyte is injected into the battery cell 21 , the bottom wall 41 of the protection component 40 is impacted by the electrolyte first. The thickness of the bottom wall 41 is large enough to effectively resist the impact force of the electrolyte, thereby ensuring the normal use of the protection component 40 .

[0094] The end cap assembly 30, battery cell 21, battery 10 and electrical device of the embodiment of the present application are described above. The manufacturing method of the battery cell 21 of the embodiment of the present application will be described below. For the parts not described in detail, please refer to the aforementioned embodiments.

[0095] The present application also provides a method for manufacturing a battery cell 21, comprising: step S100, providing a shell 22, the shell 22 is provided with an opening 221; step S200, providing an end cover assembly 30, the end cover assembly 30 comprising: an end cover 31, the end cover 31 is provided with an injection hole 311, the injection hole 311 is used to inject electrolyte into the battery cell 21; and an insulating member 32, the insulating member 32 is provided with a protective assembly 40 on one side of the injection hole 311 close to the inside of the battery cell 21 along the thickness direction of the end cover 31, the protective assembly 40 is arranged opposite to the injection hole 311, the protective assembly 40 includes an opening and closing mechanism 422, the opening and closing mechanism 422 is configured to open when injecting electrolyte into the battery cell 21 to allow electrolyte to enter the battery cell 21, and close after the injection of electrolyte into the battery cell 21 is completed; step S300, covering the opening 221 with the end cover assembly 30.

[0096] The protection component 40 can reduce the contact area between the inside of the battery cell 21 and the outside air, reduce the influence of the outside water vapor on the inside of the battery cell 21, and increase the service life of the battery cell 21.

[0097] The execution order of step S100 and step S200 is not limited in this application. For example, step S100 is executed first, and then step S200; or step S200 is executed first, and then step S100.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein, but these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An end cap assembly for a battery cell, characterized in that: include: An end cover, wherein the end cover is provided with a liquid injection hole, and the liquid injection hole is used to inject electrolyte into the battery cell; and An insulating component, wherein a protective component is arranged on a side of the injection hole close to the interior of the battery cell along the thickness direction of the end cover, the protective component is arranged opposite to the injection hole, and the protective component includes an opening and closing mechanism, and the opening and closing mechanism is configured to open when the electrolyte is injected into the battery cell to allow the electrolyte to enter the interior of the battery cell, and close after the injection of the electrolyte into the battery cell is completed; the protective component includes a bottom wall and a side wall, the opening and closing mechanism is arranged on the side wall, and the side wall includes a plurality of connecting columns, the plurality of connecting columns are arranged at intervals along the circumference of the injection hole, two adjacent connecting columns among the plurality of connecting columns are arranged at both ends of the opening and closing mechanism, and the opening and closing mechanism is rotatably connected to the connecting columns.

2. The end cap assembly according to claim 1, characterized in that: The protection component includes a plurality of the opening and closing mechanisms, and the plurality of the opening and closing mechanisms are arranged along the thickness direction of the end cover.

3. The end cap assembly according to claim 1, characterized in that: The protection component includes a plurality of the opening and closing mechanisms, and the plurality of the opening and closing mechanisms are arranged along the circumference of the liquid injection hole.

4. The end cap assembly according to claim 1, characterized in that: The connecting column is provided with a connecting hole, and the opening and closing mechanism is provided with a connecting shaft, and the connecting shaft is arranged in the connecting hole.

5. The end cap assembly according to claim 4, characterized in that: Along the thickness direction of the end cover, the connecting column is provided with a plurality of connecting holes, the protective component includes a plurality of the opening and closing mechanisms, the plurality of connecting holes are arranged corresponding to the plurality of the opening and closing mechanisms, and the distance between two adjacent connecting holes is greater than the height of the opening and closing mechanism.

6. The end cap assembly according to claim 4, characterized in that: Along the thickness direction of the end cover, the central axis of the connecting shaft is located above the central axis of the opening and closing mechanism.

7. The end cap assembly according to claim 1, characterized in that: The distance between two adjacent connecting columns is greater than the length of the opening and closing mechanism along the circumference of the liquid injection hole.

8. The end cap assembly according to claim 1, characterized in that: Along the opening and closing direction of the opening and closing mechanism, the thickness of the opening and closing mechanism is between 0.5mm and 3mm.

9. The end cap assembly according to claim 1, characterized in that: Along the thickness direction of the end cover, the projection of the injection hole is located within the projection of the protective component.

10. The end cap assembly according to claim 1, characterized in that: The thickness of the bottom wall is not less than the thickness of the side wall.

11. A battery cell, characterized in that: include: A housing, wherein the housing is provided with an opening; The end cap assembly according to any one of claims 1 to 10, wherein the end cap assembly is used to cover the opening.

12. A battery, characterized in that: include: The battery cell according to claim 11; as well as The box body is used to accommodate the battery cells.

13. An electrical device, characterized in that: include: The battery of claim 12, wherein the battery is used to provide electrical energy.

14. A method for manufacturing a battery cell, characterized in that: The method comprises: Providing a housing, wherein the housing is provided with an opening; An end cap assembly is provided, the end cap assembly comprising: an end cover, wherein the end cover is provided with a liquid injection hole, and the liquid injection hole is used to inject electrolyte into the interior of the battery cell; and an insulating member, wherein a protective component is provided on one side of the injection hole close to the interior of the battery cell along the thickness direction of the end cover, the protective component is arranged opposite to the injection hole, the protective component comprises an opening and closing mechanism, the opening and closing mechanism is configured to open when injecting electrolyte into the battery cell to allow electrolyte to enter the interior of the battery cell, and close after the injection of electrolyte into the battery cell is completed, the protective component comprises a bottom wall and a side wall, the opening and closing mechanism is arranged on the side wall, the side wall comprises a plurality of connecting columns, the plurality of connecting columns are arranged at intervals along the circumference of the injection hole, two adjacent connecting columns among the plurality of connecting columns are arranged at both ends of the opening and closing mechanism, and the opening and closing mechanism is rotatably connected to the connecting columns; The end cap assembly is used to cover the opening.

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