Electrode assemblies, battery cells, batteries and electrical equipment

Abstract

The present application provides an electrode assembly, a battery cell, a battery, an electrical device, an electrode assembly manufacturing device and a method, and relates to the field of battery technology. The electrode assembly includes a main body and a tab portion; the tab portion is provided at one end of the main body, and the tab portion has a tab end face provided away from the main body; the tab portion is provided with a guide groove that is recessed from the tab end face in a direction close to the main body, and the guide groove is used to guide the electrolyte to diffuse around the main body. The tab portion is provided with a guide groove that is recessed from the tab end face in a direction close to the main body, and the guide groove can guide the electrolyte to diffuse around the main body, which is equivalent to providing a channel for the diffusion of the electrolyte, which is conducive to the electrode assembly being fully infiltrated by the electrolyte, so that the battery cell using the electrode assembly has good cycle performance and reduces the risk of lithium plating in the battery cell, thereby improving the performance of the battery cell.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and more specifically, to an electrode assembly, a battery cell, a battery, an electrical device, and a manufacturing device and method for an electrode assembly. Background Art

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

[0003] In the development of battery technology, in addition to improving battery safety, battery performance is also an important issue that cannot be ignored. Batteries need to have good battery performance to ensure the normal operation of electrical devices. Therefore, how to improve battery performance is an urgent problem to be solved in the field of battery technology. Summary of the Invention

[0004] The embodiments of the present application provide an electrode assembly, a battery cell, a battery, an electrical device, and an apparatus and method for manufacturing the electrode assembly to improve the performance of the battery.

[0005] In a first aspect, an embodiment of the present application provides an electrode assembly, comprising a main body and a pole ear portion; the pole ear portion is arranged at one end of the main body portion, and the pole ear portion has a pole ear end face arranged away from the main body portion; wherein the pole ear portion is provided with a guide groove recessed from the pole ear end face in a direction close to the main body portion, and the guide groove is used to guide the electrolyte to diffuse around the main body portion.

[0006] In the above technical solution, a guide groove is provided on the pole ear, which is recessed from the end surface of the pole ear toward the main body. The guide groove can guide the electrolyte to diffuse to the surrounding of the main body, which is equivalent to providing a channel for the diffusion of the electrolyte, which is conducive to the electrode assembly being fully infiltrated by the electrolyte, so that the battery cell using the electrode assembly has good cycle performance and reduces the risk of lithium plating in the battery cell, thereby improving the performance of the battery cell.

[0007] In some embodiments of the first aspect of the present application, the guide groove is formed by pressing the end surface of the tab.

[0008] In this technical solution, the guide grooves are formed by ramming the end faces of the tabs, a simple and quick molding method that improves molding efficiency. Furthermore, ramming minimizes the likelihood of damaging the tabs and the body, reducing the risk of compromising the electrode assembly's conductivity. It also compacts the tabs toward the body, reducing the volume of the electrode assembly.

[0009] In some embodiments of the first aspect of the present application, the electrode assembly further includes: a center hole, a portion of the center hole is formed in the main body, and the center hole passes through the end face of the tab, and the guide groove is connected to the center hole.

[0010] In the above technical solution, the guide groove is connected to the central hole, and the electrolyte in the central hole can diffuse to the surrounding of the main body through the guide groove, and the electrolyte around the main body can also flow to the central hole, which is conducive to sufficient wetting of the electrode assembly.

[0011] In some embodiments of the first aspect of the present application, the guide groove passes through the edge of the pole lug portion in a direction perpendicular to the axis of the central hole and in a direction away from the axis of the central hole.

[0012] In the above technical solution, the guide groove runs through the edge of the pole ear portion, so that the electrolyte can diffuse to the outside of the edge of the main body portion, so that the electrolyte can quickly and fully infiltrate the electrode assembly.

[0013] In some embodiments of the first aspect of the present application, the width of the guide groove gradually increases in a direction perpendicular to the axis of the central hole and in a direction away from the axis of the central hole.

[0014] In the above technical solution, the width of the guide groove gradually increases in the direction perpendicular to the axis of the center hole and along the direction away from the axis of the center hole. In other words, the width of the guide groove gradually increases from the center hole to the edge close to the pole ear, which is conducive to the rapid flow of electrolyte from the center hole to the edge of the pole ear, thereby improving the wetting efficiency.

[0015] In some embodiments of the first aspect of the present application, the minimum width of the guide groove is smaller than the aperture of the central hole.

[0016] In the above technical solution, the minimum width of the guide groove is smaller than the aperture of the central hole, so that the electrolyte can diffuse to the surrounding at a reasonable flow rate, ensuring uniform infiltration of the electrode assembly.

[0017] In some embodiments of the first aspect of the present application, the guide grooves are grooves of equal width.

[0018] In the above technical solution, the guide groove is of equal width structure, which is convenient for manufacturing and forming.

[0019] In some embodiments of the first aspect of the present application, the width of the guide groove is greater than the aperture of the central hole.

[0020] In the above technical solution, the width of the guide groove is greater than the aperture of the central hole, which is beneficial to increasing the flow rate of the electrolyte in the guide groove, thereby allowing the electrolyte to diffuse quickly to the surroundings and improving the infiltration efficiency.

[0021] In some embodiments of the first aspect of the present application, the sidewalls of the guide groove are arc surfaces.

[0022] In the above technical solution, the sidewalls of the guide groove are arc-shaped, which is beneficial to improving the efficiency of the electrolyte diffusion to the surroundings, thereby improving the infiltration efficiency.

[0023] In some embodiments of the first aspect of the present application, a plurality of guide grooves are formed on the end surface of the tab, and the plurality of guide grooves are arranged at intervals around the central hole.

[0024] In the above technical solution, a plurality of the guide grooves are formed on the end surface of the tab, which can improve the efficiency of the electrolyte diffusion to the surrounding of the main body, thereby improving the infiltration efficiency.

[0025] In some embodiments of the first aspect of the present application, a plurality of guide grooves are evenly spaced around the central hole.

[0026] In the above technical solution, the plurality of guide grooves are evenly spaced along the circumference of the electrode assembly so that the electrolyte diffused around the main body is evenly distributed, so that the electrode assembly can be evenly infiltrated.

[0027] In a second aspect, an embodiment of the present application provides a battery cell comprising a housing and the electrode assembly provided in the embodiment of the first aspect; the housing is used to accommodate the electrode assembly, and the housing has an electrode output portion, which is used to connect to the end face of the tab.

[0028] In the above technical solution, the electrode assembly is provided with a guide groove on the pole ear portion, which is recessed from the pole ear end surface toward the main body. The guide groove can guide the electrolyte to diffuse to the surrounding of the main body, which is equivalent to providing a channel for the diffusion of the electrolyte, which is conducive to the electrode assembly being fully infiltrated by the electrolyte, so that the battery cell has good cycle performance and reduces the risk of lithium plating of the battery cell, thereby improving the performance of the battery cell.

[0029] In some embodiments of the second aspect of the present application, the battery cell further includes: a current collecting component accommodated in the housing, the current collecting component abutting against the end surface of the tab, and the current collecting component connected to the electrode output portion.

[0030] In the above technical solution, the current collecting component is against the end face of the electrode tab and is connected to the electrode output part. Due to the setting of the guide groove, an electrolyte flow channel is formed between the current collecting component and the end face, which is conducive to the electrolyte infiltration of the electrode assembly.

[0031] In some embodiments of the second aspect of the present application, the tab end surface is welded to the current collecting member to form a weld mark on the tab end surface extending radially or circumferentially of the electrode assembly.

[0032] In the above technical solution, a weld mark extending radially or circumferentially of the electrode assembly is formed on the end face of the electrode tab, thereby increasing the welding area between the end face of the electrode tab and the current collecting component and improving the flow conducting capacity.

[0033] In a third aspect, an embodiment of the present application provides a battery, comprising the battery cell provided in the embodiment of the second aspect.

[0034] In a fourth aspect, an embodiment of the present application provides an electrical device, comprising the battery provided in the embodiment of the third aspect.

[0035] In a fifth aspect, an embodiment of the present application provides an electrode assembly manufacturing device, comprising a providing device and a pressing device; the providing device is configured to provide an electrode assembly, the electrode assembly comprising a main body portion and a pole ear portion, the pole ear portion being arranged at one end of the main body portion, the pole ear portion having a pole ear end face arranged away from the main body portion; the pressing device is configured to press the pole ear end face to form a guide groove in the pole ear portion that is recessed from the pole ear end face toward the main body portion, the guide groove being used to guide the electrolyte to diffuse around the main body portion.

[0036] In the above technical solution, a guide groove is provided on the pole ear portion, which is recessed from the end surface of the pole ear toward the direction close to the body. The guide groove can guide the electrolyte to diffuse toward the surrounding of the body portion, which is equivalent to providing a channel for the diffusion of the electrolyte, which is conducive to the electrode assembly being fully infiltrated by the electrolyte, so that the battery cell using this electrode assembly has good cycle performance and reduces the risk of lithium deposition in the battery cell. The pole ear end surface is pressed by a pressing device to form the guide groove. The molding method is simple and fast, which can improve molding efficiency. In addition, the possibility of damaging the pole ear and the body portion by pressing is very small, reducing the risk of affecting the conductivity of the electrode assembly; it can also compact the pole ear portion in the direction close to the body portion, reducing the volume of the electrode assembly.

[0037] In a sixth aspect, an embodiment of the present application provides a method for manufacturing an electrode assembly, comprising:

[0038] An electrode assembly is provided, the electrode assembly comprising a body portion and a tab portion, the tab portion being disposed at one end of the body portion and having a tab end surface disposed away from the body portion;

[0039] The end surface of the tab is pierced to form a guide groove on the tab portion, which is recessed from the end surface of the tab toward the main body portion. The guide groove is used to guide the electrolyte to diffuse around the main body portion.

[0040] In the above technical solution, the guide groove can guide the electrolyte to diffuse around the main body, which is equivalent to providing a channel for the diffusion of the electrolyte, which is conducive to the electrode assembly being fully infiltrated by the electrolyte, so that the battery cells using this electrode assembly have good cycle performance and reduce the risk of lithium deposition in the battery cells. The guide groove is formed on the end face of the pole ear by pressing. The molding method is simple and fast, which can improve the molding efficiency. In addition, the pressing method is unlikely to damage the pole ear and the main body, reducing the risk of affecting the conductivity of the electrode assembly; it can also compact the pole ear in the direction close to the main body, reducing the volume of the electrode assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0042] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0043] Figure 2 A schematic diagram of the structure of a battery provided in some embodiments of the present application;

[0044] Figure 3 An exploded view of a battery cell provided in some embodiments of the present application;

[0045] Figure 4 A schematic diagram of the structure of an electrode assembly provided in some embodiments of the present application;

[0046] Figure 5 An axial view of an electrode assembly provided for some embodiments of the present application;

[0047] Figure 6 Schematic diagram of the structure of electrode assemblies provided in other embodiments of the present application;

[0048] Figure 7 for Figure 6 An axial view of the electrode assembly in FIG;

[0049] Figure 8 A schematic structural diagram of an electrode assembly provided in some other embodiments of the present application;

[0050] Figure 9 for Figure 8 An axial view of the electrode assembly in FIG;

[0051] Figure 10 Schematic diagram of the current collecting component abutting against the end face of the tab;

[0052] Figure 11 A schematic structural diagram of an electrode assembly manufacturing device provided in some embodiments of the present application;

[0053] Figure 12 A flowchart of a method for manufacturing an electrode assembly provided in some embodiments of the present application.

[0054] Icons: 1000-Vehicle; 100-Battery; 10-Box; 11-Installation Space; 12-First Part; 13-Second Part; 20-Battery Cell; 21-Casing; 211-Shell; 2111-Opening; 2112-Bottom Shell; 212-End Cap; 213-Electrode Output Port; 22-Electrode Assembly; 221-Main Body; 222-Electrode Lug; 222a-Positive Electrode Lug; 222b-Negative Electrode Tab; 2221-tab end face; 2222-guide groove; 2223-edge of the tab; 223-center hole; 23-current collecting component; 23a-positive current collecting component; 23b-negative current collecting component; 24-insulating member; 25-sealing member; 26-guide channel; 200-controller; 300-motor; 2000-electrode assembly manufacturing equipment; 2100-providing device; 2200-pressing device. DETAILED DESCRIPTION

[0055] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0056] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0057] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0058] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0059] In the description of the embodiments of the present application, it should be noted that the indicated orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of the application is conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. These are merely for the convenience of describing the present application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present application. In addition, the terms "first," "second," "third," etc. are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0060] Currently, market developments indicate that power batteries are becoming increasingly widely used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As power battery applications continue to expand, market demand is also growing.

[0061] A battery cell includes a housing and an electrode assembly, with the electrode assembly 22 housed within the housing. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. The battery cell primarily operates by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive electrode collector. The portion of the positive electrode collector not coated with the positive active material layer protrudes from the portion coated with the positive active material layer, and the portion of the positive electrode collector not coated with the positive active material layer serves as the positive electrode tab. For lithium-ion batteries, for example, the positive electrode current collector can be made of aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative electrode collector. The portion of the negative electrode collector not coated with the negative active material layer protrudes from the portion coated with the negative active material layer, and the portion of the negative electrode collector not coated with the negative active material layer serves as the negative electrode tab. The negative electrode current collector can be made of copper, and the negative electrode active material can be carbon or silicon, among others. To ensure that high currents can pass without fusing, multiple positive electrode tabs are stacked together, and multiple negative electrode tabs are stacked together. The separator can be made of materials such as PP (polypropylene) or PE (polyethylene). Furthermore, the electrode assembly can be a wound or laminated structure, but the embodiments of the present application are not limited thereto.

[0062] The electrode assembly's tabs can be die-cut or undie-cut. The inventors discovered that to reduce the volume of the electrode assembly and facilitate welding of the tabs to the current collector plate, the tabs, especially the full tabs, need to be flattened. This flattened tab forms a tab end face, which tightly adheres to and is welded to the current collector plate. This makes it difficult for the electrolyte to penetrate the electrode assembly through the tab end face, severely impacting the performance of the battery cells.

[0063] Based on the above considerations, in order to alleviate the problem that the end face of the pole ear formed after the pole ear is flattened is tightly fitted and welded to the collecting plate, which makes it difficult for the electrolyte to infiltrate the electrode assembly from the end face of the pole ear, the inventor has designed an electrode assembly after in-depth research. By providing a guide groove on the pole ear that is recessed from the end face of the pole ear toward the main body, the guide groove can guide the electrolyte to diffuse to the surrounding area of ​​the main body, which is equivalent to providing a channel for the diffusion of the electrolyte, which is conducive to the electrode assembly being fully infiltrated by the electrolyte, so that the battery cell using the electrode assembly has good cycle performance and reduces the risk of lithium plating in the battery cell, thereby improving the performance of the battery cell.

[0064] The electrode assembly disclosed in the embodiments of this application can be used, but is not limited to, in electrical equipment such as vehicles, ships, or aircraft. A battery cell, battery, or the like equipped with the electrode assembly disclosed in this application can be used to form a power supply system for the electrical device. This facilitates sufficient electrolyte infiltration of the electrode assembly 22, resulting in good cycle performance for the battery cell using the electrode assembly and reducing the risk of lithium deposition in the battery cell, thereby improving the performance of the battery cell.

[0065] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0066] Electrical equipment can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and electric tools, etc. Vehicles can be fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical equipment.

[0067] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle 1000 as an example.

[0068] Please refer to Figure 1 , Figure 1This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of the present application. A battery 100 is disposed within the vehicle 1000, and the battery 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery 100 can be used to power the vehicle 1000, for example, as the operating power source of the vehicle 1000.

[0069] The vehicle 1000 may further include a controller 200 and a motor 300 . The controller 200 is used to control the battery 100 to supply power to the motor 300 , for example, to meet the power requirements of the vehicle 1000 during startup, navigation, and driving.

[0070] In some embodiments of the present application, the battery 100 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0071] Please refer to Figure 2 , Figure 2 The battery 100 is a schematic structural diagram of some embodiments of the present application. The battery 100 includes a housing 10 and a battery cell 20 , wherein the battery cell 20 is accommodated in the housing 10 .

[0072] The housing 10 is used to provide an installation space 11 for the battery cells 20. In some embodiments, the housing 10 may include a first portion 12 and a second portion 13, which overlap to define the installation space 11 for accommodating the battery cells 20. The connection between the first portion 12 and the second portion 13 can be sealed by a seal 25 (not shown), which may be a sealing ring, sealant, or the like.

[0073] The first portion 12 and the second portion 13 can have various shapes, such as a rectangular parallelepiped, a cylinder, etc. The first portion 12 can be a hollow structure with an opening on one side to form a cavity for accommodating the battery cell 20. The second portion 13 can also be a hollow structure with an opening on one side to form a cavity for accommodating the battery cell 20. The open side of the second portion 13 covers the open side of the first portion 12, thereby forming the box 10 with the installation space 11. Of course, the first portion 12 can also be a hollow structure with an opening on one side to form a cavity for accommodating the battery cell 20, and the second portion 13 can be a plate-like structure. The second portion 13 covers the open side of the first portion 12, thereby forming the box 10 with the installation space 11.

[0074] In the battery 100, there can be one or more battery cells 20. If there are multiple battery cells 20, the multiple battery cells 20 can be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 can be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 20 can be housed within the housing 10. Alternatively, multiple battery cells 20 can be first connected in series, in parallel, or in a hybrid connection to form a battery module, and then the multiple battery modules can be connected in series, in parallel, or in a hybrid connection to form a single unit and housed within the housing 10. The battery cells 20 can be cylindrical, flat, rectangular, or other shapes. Figure 2 The battery cell 20 is shown as a cylinder by way of example.

[0075] In some embodiments, the battery 100 may further include a busbar component (not shown), and the multiple battery cells 20 may be electrically connected via the busbar component to achieve series connection, parallel connection, or mixed connection of the multiple battery cells 20 .

[0076] Please refer to Figure 3 , Figure 3 This is an exploded view of a battery cell 20 provided in some embodiments of the present application. The battery cell 20 may include a housing 21 and an electrode assembly 22. The housing 21 includes a shell 211 and an end cap 212. The housing 21 has an opening 2111, and the electrode assembly 22 is accommodated within the shell 211. The end cap 212 is used to seal the opening 2111.

[0077] The housing 21 can have various shapes, such as a cylinder, a cuboid, etc. The shape of the housing 21 can be determined based on the specific shape of the electrode assembly 22. For example, if the electrode assembly 22 has a cylindrical structure, the housing 21 can be a cylindrical structure; if the electrode assembly 22 has a cuboid structure, the housing 21 can be a cuboid structure. Figure 3 The case where the housing 21 and the electrode assembly 22 are cylindrical is exemplarily shown.

[0078] The shell 21 may be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0079] The end cap 212 is used to seal the opening 2111 of the shell 211 of the outer shell 21 to form a sealed accommodation space (not shown in the figure), which is used to accommodate the electrode assembly 22. The accommodation space is also used to accommodate an electrolyte, such as an electrolyte. An electrode output portion 213 for outputting the electrical energy of the electrode assembly 22 can be provided on the end cap 212, for example, an electrode terminal is provided on the end cap 212. The electrode terminal in the end cap 212 assembly is used to electrically connect to the electrode assembly 22, that is, the electrode terminal is electrically connected to the tab of the electrode assembly 22, for example, the electrode terminal is connected to the tab through the current collecting member 23 to achieve electrical connection between the electrode terminal and the tab.

[0080] It should be noted that the housing 211 may have one or two openings 2111. If the housing 211 has one opening 2111, the end cap 212 may also be one. Two electrode terminals may be provided on the end cap 212. The two electrode terminals are respectively used to electrically connect to the positive electrode tab 222a and the negative electrode tab 222b of the electrode assembly 22. The two electrode terminals on the end cap 212 are respectively a positive electrode terminal and a negative electrode terminal. If the housing 211 has two openings 2111, for example, the two openings 2111 are provided on opposite sides of the housing 211, the end cap 212 may also be two, with the two end caps 212 respectively covering the two openings 2111 of the housing 211. In this case, the electrode terminal provided on one end cap 212 may be a positive electrode terminal, which is used to electrically connect to the positive electrode tab 222a of the electrode assembly 22; and the electrode terminal on the other end cap 212 may be a negative electrode terminal, which is used to electrically connect to the negative electrode sheet of the electrode assembly 22.

[0081] In an embodiment where there is only one end cap 212, only one electrode terminal may be provided on the end cap 212, and the electrode terminal is used to electrically connect to one of the positive electrode tab 222a and the negative electrode tab 222b of the electrode assembly 22, and the other of the positive electrode tab 222a and the negative electrode tab 222b of the electrode assembly 22 is electrically connected to the housing 21. Figure 3 As shown, the positive electrode tab 222a and the negative electrode tab 222b of the electrode assembly 22 are respectively disposed at the axial ends of the electrode assembly 22. The positive electrode tab 222a of the electrode assembly 22 is electrically connected to the electrode terminal on the end cap 212 via the positive current collecting member 23a. The negative electrode tab 222b of the electrode assembly 22 is electrically connected to the housing 211 via the negative current collecting member 23b. For example, the negative electrode tab 222b is electrically connected to the bottom shell 2112 of the housing 211 via the negative current collecting member 23b. The electrode assembly 22 also includes an insulating member 24 and a sealing member 25. The insulating member 24 is disposed between the electrode terminal and the end cap 212 to provide insulation between the electrode terminal and the end cap 212. The sealing member 25 is disposed between the electrode terminal and the end cap 212 to provide a seal between the electrode terminal and the end cap 212.

[0082] The electrode assembly 22 may include a positive electrode sheet (not shown), a negative electrode sheet (not shown), and a separator (not shown). The electrode assembly 22 may be a wound structure formed by winding the positive electrode sheet, separator, and negative electrode sheet, or a stacked structure formed by stacking the positive electrode sheet, separator, and negative electrode sheet. The electrode assembly 22 also includes a positive electrode tab 222a (not shown) and a negative electrode tab 222b (not shown). The positive electrode tab 222a may be a positive electrode current collector in the positive electrode sheet that is not coated with a positive electrode active material layer, and the negative electrode tab 222b may be a negative electrode current collector in the negative electrode sheet that is not coated with a negative electrode active material layer.

[0083] like Figure 3 、 Figure 4 As shown, Figure 4 This is a schematic diagram of the structure of an electrode assembly 22 provided in some embodiments of the present application. The electrode assembly 22 includes a body portion 221 and a tab portion 222. The tab portion 222 is disposed at one end of the body portion 221 and has a tab end surface 2221 disposed away from the body portion 221. The tab portion 222 is provided with a guide groove 2222 recessed from the tab end surface 2221 toward the body portion 221. The guide groove 2222 is used to guide the electrolyte to diffuse around the body portion 221.

[0084] The tab portion 222 is a flattened tab. The tab portion 222 can be either the positive tab 222a or the negative tab 222b. The electrode assembly 22 can have the guide groove 2222 provided on the tab end surface 2221 of the positive tab 222a, or the negative tab 222b, or both the tab end surface 2221 of the positive tab 222a and the negative tab 222b.

[0085] A guide groove 2222 is provided on the pole ear portion 222, which is recessed from the pole ear end surface 2221 toward the direction close to the main body. The guide groove 2222 can guide the electrolyte to diffuse toward the surrounding of the main body portion 221, which is equivalent to providing a channel for the diffusion of the electrolyte, which is beneficial for the electrode assembly 22 to be fully infiltrated by the electrolyte, so that the battery cell 20 using the electrode assembly 22 has good cycle performance and reduces the risk of lithium plating of the battery cell 20, thereby improving the performance of the battery cell 20.

[0086] There are many ways to form the guide groove 2222 on the tab end surface 2221 of the tab portion 222 , such as cutting, etc. In some embodiments, the guide groove 2222 is formed by pressing the tab end surface 2221 .

[0087] The pressing process involves the pressing surface of the pressing device 2200 contacting the end face 2221 of the tab, and applying pressure in a direction close to the body 221 to compact and flatten the tab to form the tab portion 222. A protrusion can be provided on the pressing surface of the pressing device 2200, so that after the pressing is completed, a guide groove 2222 matching the shape of the protrusion is formed on the end face 2221 of the tab.

[0088] Forming the flow guide groove 2222 by ramming the end surface 2221 of the electrode tab is a simple and quick process, improving molding efficiency. Furthermore, ramming minimizes the likelihood of damaging the tab 222 and body 221, reducing the risk of compromising the flow conduction capability of the electrode assembly 22. Furthermore, the tab 222 is compacted toward the body 221, reducing the volume of the electrode assembly 22 and facilitating welding to the current collecting member 23.

[0089] Please continue to refer to Figure 4 In some embodiments, the electrode assembly 22 further includes: a center hole 223 , a portion of the center hole 223 is formed in the main body 221 , and the center hole 223 passes through the tab end surface 2221 , and the guide groove 2222 is connected to the center hole 223 .

[0090] For the wound electrode assembly 22, the center hole 223 is the wound center hole 223 of the electrode assembly 22. Part of the center hole 223 is formed in the main body 221, and the other part of the center hole 223 is formed in the pole ear 222 and passes through the pole ear end face 2221. Along the radial direction of the electrode assembly 22, one end of the guide groove 2222 is connected to the center hole 223. The radial direction of the electrode assembly 22 is the direction perpendicular to the axis of the center hole 223. In the direction perpendicular to the axis of the center hole 223 and in the direction away from the axis of the center hole 223, the other end of the guide groove 2222 may pass through the edge 2223 of the pole ear, or may not pass through the edge 2223 of the pole ear.

[0091] Of course, for the laminated electrode assembly 22 , the center hole 223 may be a center hole 223 reserved in the middle.

[0092] The guide groove 2222 is connected to the central hole 223. The electrolyte in the central hole 223 can diffuse to the surrounding of the main body 221 through the guide groove 2222, and can also make the electrolyte around the main body 221 flow to the central hole 223, which is conducive to the electrode assembly 22 being fully infiltrated.

[0093] Please refer to Figure 4 、 Figure 5 , Figure 5 This is an axial view of the electrode assembly 22 provided in some embodiments of the present application. In some embodiments, the guide groove 2222 penetrates the edge 2223 of the electrode lug in a direction perpendicular to the axis of the central hole 223 and in a direction away from the axis of the central hole 223 .

[0094] The edge 2223 of the electrode ear portion is the outer peripheral surface of the electrode ear portion 222 arranged around the axis of the center hole 223. It can be understood that along the direction perpendicular to the axis of the center hole 223, the outer periphery of the body portion 221 is connected to the center hole 223 of the electrode assembly 22 through the guide groove 2222.

[0095] The guide groove 2222 passes through the edge 2223 of the pole ear, allowing the electrolyte to diffuse to the edge of the main body 221 and also allowing the electrolyte to flow from the edge of the main body to the center hole 223, so that the electrolyte can quickly and fully infiltrate the electrode assembly 22.

[0096] like Figure 4 、 Figure 5 As shown, in some embodiments, the width of the guide groove 2222 gradually increases in a direction perpendicular to the axis of the central hole 223 and in a direction away from the axis of the central hole 223 .

[0097] Figure 4 、 5 In the embodiment, the guide groove 2222 is fan-shaped. Of course, in other embodiments, the guide groove 2222 may be formed in other shapes. The width of the guide groove 2222 may also have other changing trends. For example, in a direction perpendicular to the axis of the center hole 223 and in a direction away from the axis of the center hole 223, the width of the guide groove 2222 may first gradually increase and then maintain a consistent width.

[0098] In the direction perpendicular to the axis of the center hole 223 and along the direction away from the axis of the center hole 223, the width of the guide groove 2222 gradually increases. In other words, from the center hole 223 to the edge 2223 close to the pole ear, the width of the guide groove 2222 gradually increases, which is conducive to the rapid flow of electrolyte from the center hole 223 to the edge 2223 of the pole ear, thereby improving the wetting efficiency.

[0099] Please continue to see Figure 5 , the minimum width of the guide groove 2222 is smaller than the aperture of the center hole 223 .

[0100] Figure 5 In the embodiment, the width of the guide groove 2222 gradually increases in a direction perpendicular to the axis of the center hole 223 and in a direction away from the axis of the center hole 223. The minimum width of the guide groove 2222 is at the end closest to the axis of the center hole 223, that is, H1 < D1. The aperture is the diameter of the center hole 223. In embodiments where the center hole 223 is not circular, the aperture of the center hole 223 may be the diameter obtained by converting the center hole 223 into a circular hole.

[0101] The minimum width of the guide groove 2222 is smaller than the aperture of the central hole 223 , so that the electrolyte can diffuse to the surroundings at a reasonable flow rate, ensuring uniform infiltration of the electrode assembly 22 .

[0102] Please refer to Figure 6 、 Figure 7 , Figure 6 This is a schematic structural diagram of the electrode assembly 22 provided in some other embodiments of the present application. Figure 7 for Figure 62. In other embodiments, the guide grooves 2222 are of equal width.

[0103] The guide groove 2222 is a groove of equal width, which means that the groove width at any position of the guide groove 2222 is equal in the direction perpendicular to the axis of the central hole 223.

[0104] The guide grooves 2222 are of equal width, which facilitates manufacturing and molding.

[0105] Please continue to refer to Figure 6 、 Figure 7 In some embodiments, the width of the guide groove 2222 is greater than the diameter of the central hole 223 .

[0106] Figure 6 、 Figure 7 In the embodiment, the groove width H2 of the guide groove 2222 and the aperture D1 of the center hole 223 satisfy H2=D1.

[0107] In the embodiment where the guide groove 2222 is a groove of non-uniform width, the width of the guide groove 2222 is greater than the aperture of the central hole 223 , which means that the minimum width of the guide groove 2222 is greater than the aperture of the central hole 223 .

[0108] The width of the guide groove 2222 is greater than the aperture of the central hole 223, which is beneficial to increasing the flow rate of the electrolyte in the guide groove 2222, thereby allowing the electrolyte to quickly diffuse to the surroundings and improving the infiltration efficiency.

[0109] The guide groove 2222 has two groove side walls arranged opposite to each other, and the two opposite groove side walls define the width of the guide groove 2222. The groove side walls of the guide groove 2222 can be surfaces of different forms. For example, Figure 8 、 Figure 9 As shown, Figure 8 This is a schematic structural diagram of the electrode assembly 22 provided in some embodiments of the present application. Figure 9 for Figure 8 22. In some embodiments, the sidewalls of the guide grooves 2222 are arcuate.

[0110] The arc surface can be a convex arc surface or a concave arc surface. A concave arc surface refers to a groove sidewall that is concave away from the interior of the guide groove 2222. A convex arc surface refers to a groove sidewall that is convex toward the interior of the guide groove 2222. Figure 7 、 Figure 8 The figure shows that the groove sidewall is in the form of a concave arc surface.

[0111] In other embodiments, the sidewalls of the guide groove 2222 may be flat (eg Figure 4-Figure 7 shown).

[0112] The sidewalls of the guide groove 2222 are arc-shaped, which is beneficial to improving the efficiency of the electrolyte diffusion to the surroundings, thereby improving the infiltration efficiency.

[0113] Please refer to Figure 4-Figure 9 In some embodiments, a plurality of guide grooves 2222 are formed on the tab end surface 2221 , and the plurality of guide grooves 2222 are arranged at intervals around the central hole 223 .

[0114] "Two" means two or more. A welding zone is defined between two adjacent guide grooves 2222. The welding zone is used to weld the electrode lug 222 to the electrode output portion 213, thereby achieving electrical connection between the electrode lug 222 and the electrode output portion 213. The shapes of the multiple guide grooves 2222 can be the same or different. The groove widths of the multiple guide grooves 2222 can be the same or different.

[0115] In some embodiments, two adjacent guide grooves 2222 are connected to each other along the circumference of the electrode assembly 22. Figure 6 、 Figure 7 If the width of the guide groove 2222 is greater than the diameter of the central hole 223, two adjacent guide grooves 2222 are connected along the circumference of the electrode assembly 22. If the number of guide grooves 2222 is sufficient, two adjacent guide grooves 2222 can also be connected along the circumference of the electrode assembly 22.

[0116] In other embodiments, only one guide groove 2222 may be provided on the tab end surface 2221 .

[0117] A plurality of guide grooves 2222 are formed on the tab end surface 2221 , which can improve the efficiency of the electrolyte diffusing to the periphery of the main body 221 , thereby improving the wetting efficiency.

[0118] Please continue to see Figure 4-Figure 9 In some embodiments, the plurality of guide grooves 2222 are evenly spaced around the central hole 223 .

[0119] The central angles of two adjacent guide grooves 2222 are the same. Of course, according to actual needs, multiple guide grooves 2222 can also be arranged around the central hole 223 in a non-uniform state.

[0120] The plurality of guide grooves 2222 are evenly spaced along the circumference of the electrode assembly 22 so that the electrolyte diffused around the main body 221 is evenly distributed, so that the electrode assembly 22 can be evenly infiltrated.

[0121] An embodiment of the present application provides a battery cell 20, which includes a shell 21 and an electrode assembly 22 provided in any of the above embodiments; the shell 21 is used to accommodate the electrode assembly 22, and the shell 21 has an electrode output portion 213, which is used to connect to the end face 2221 of the tab.

[0122] The electrode output portion 213 can be an electrode terminal provided on the end cap 212, or it can be the shell 211 of the housing 21. The electrode output portion 213 can be directly connected to the tab end face 2221, or it can be indirectly connected to the tab end face 2221. In the embodiment in which the electrode output portion 213 is directly connected to the tab end face 2221, the surface of the electrode output portion 213 facing the tab end face 2221 abuts against the tab end face 2221, and the portion of the surface of the electrode output portion 213 facing the tab end face 2221 opposite the guide groove 2222 and the guide groove 2222 together define a channel for the flow of electrolyte.

[0123] The electrode assembly 22 is provided with a guide groove 2222 on the pole ear portion 222, which is recessed from the pole ear end surface 2221 toward the direction close to the main body. The guide groove 2222 can guide the electrolyte to diffuse toward the surrounding of the main body 221, which is equivalent to providing a channel for the diffusion of the electrolyte, which is conducive to the electrode assembly 22 being fully infiltrated by the electrolyte, so that the battery cell 20 has good cycle performance and reduces the risk of lithium plating of the battery cell 20, thereby improving the performance of the battery cell 20.

[0124] like Figure 10 As shown, Figure 10 Schematic diagram of the current collecting member 23 abutting against the tab end face 2221. In some embodiments, the battery cell 20 further includes: a current collecting member 23 accommodated in the housing 21, the current collecting member 23 abutting against the tab end face 2221, and connected to the electrode output portion 213.

[0125] The current collecting member 23 is housed within the housing 21, and the electrode tab portion 222 is indirectly connected to the electrode output portion 213 via the current collecting member 23. The surface of the current collecting member 23 facing the tab end face 2221 abuts against the tab end face 2221. The portion of the current collecting member 23 facing the tab end face 2221 that faces the guide groove 2222 and the guide groove 2222 together define a guide channel 26 for the flow of electrolyte.

[0126] The current collecting component 23 abuts against the end face 2221 of the electrode tab and is connected to the electrode output portion 213 . Due to the arrangement of the guide groove 2222 , an electrolyte flow channel is formed between the current collecting component 23 and the end face, which is conducive to the electrolyte infiltration of the electrode assembly 22 .

[0127] In some embodiments, the tab end surface 2221 is welded to the current collecting member 23 to form a weld mark on the tab end surface 2221 that extends in the radial direction or the circumferential direction of the electrode assembly 22 .

[0128] The current collecting component 23 can directly abut against the electrode tab end surface 2221 , and the electrode output portion 213 abuts against the electrode output portion 213 , thereby achieving electrical connection between the electrode tab portion 222 and the electrode output portion 213 through the current collecting component 23 .

[0129] The tab end surface 2221 forms a weld zone between two adjacent flow guide grooves 2222. Each weld zone is welded to the current collecting member 23. Laser sweeping welding can be used. The depth of the laser sweeping should be less than the depth of the flow guide grooves 2222. This ensures that after the current collecting member 23 and the weld zone are welded, a flow channel 26 is formed between the current collecting member 23 and the tab portion 222.

[0130] The weld mark may extend along the radial direction of the electrode assembly 22 or along the circumferential direction of the electrode assembly 22 , thereby increasing the welding area between the tab end face 2221 and the current collecting member 23 and improving the flow conducting capability.

[0131] An embodiment of the present application further provides a battery 100 , comprising the battery cell 20 provided in any of the above embodiments.

[0132] An embodiment of the present application further provides an electrical device, comprising the battery 100 provided in the above embodiment.

[0133] like Figure 11 As shown, the embodiment of the present application also provides an electrode assembly manufacturing device 2000, and the electrode assembly manufacturing device 2000 includes a providing device 2100 and a pressing device 2200; the providing device 2100 is configured to provide an electrode assembly 22, and the electrode assembly 22 includes a main body portion 221 and a pole ear portion 222, the pole ear portion 222 is arranged at one end of the main body portion 221, and the pole ear portion 222 has a pole ear end face 2221 arranged away from the main body portion 221; the pressing device 2200 is configured to press the pole ear end face 2221 to form a guide groove 2222 in the pole ear portion 222, which is recessed from the pole ear end face 2221 toward the direction close to the main body portion 221, and the guide groove 2222 is used to guide the electrolyte to diffuse around the main body portion 221.

[0134] The lug portion 222 is provided with a flow guide groove 2222 that is recessed from the lug end face 2221 toward the body. The flow guide groove 2222 can guide the electrolyte to diffuse toward the periphery of the body portion 221, providing a channel for the diffusion of the electrolyte. This facilitates the electrode assembly 22 to be fully infiltrated with the electrolyte, thereby ensuring that the battery cell 20 using the electrode assembly 22 has good cycle performance and reduces the risk of lithium deposition in the battery cell 20. The lug end face 2221 is pressed by the pressing device 2200 to form the flow guide groove 2222. This simple and quick molding method can improve molding efficiency. In addition, the possibility of damage to the lug portion 222 and the body portion 221 due to the pressing is very small, reducing the risk of affecting the conductivity of the electrode assembly 22. It also allows the lug portion 222 to be compacted in the direction close to the body portion 221, reducing the volume of the electrode assembly 22.

[0135] like Figure 12 As shown, the embodiment of the present application further provides a method for manufacturing an electrode assembly 22, and the method for manufacturing the electrode assembly 22 includes:

[0136] S100 , providing an electrode assembly 22 , the electrode assembly 22 including a body portion 221 and a tab portion 222 , the tab portion 222 being disposed at one end of the body portion 221 , and the tab portion 222 having a tab end surface 2221 disposed away from the body portion 221 ;

[0137] S200 , pressing the tab end surface 2221 to form a guide groove 2222 in the tab portion 222 , which is recessed from the tab end surface 2221 toward the main body portion 221 . The guide groove 2222 is used to guide the electrolyte to diffuse around the main body portion 221 .

[0138] The guide groove 2222 can guide the electrolyte to diffuse around the main body 221, which is equivalent to providing a channel for the diffusion of the electrolyte, which is conducive to the electrode assembly 22 being fully infiltrated by the electrolyte, so that the battery cell 20 using the electrode assembly 22 has good cycle performance and reduces the risk of lithium deposition in the battery cell 20. The guide groove 2222 is formed on the end face of the pole ear 2221 by pressing. The molding method is simple and fast, which can improve the molding efficiency. In addition, the pressing method is unlikely to damage the pole ear 222 and the main body 221, reducing the risk of affecting the conductivity of the electrode assembly 22; it can also compact the pole ear 222 in the direction close to the main body 221, reducing the volume of the electrode assembly 22.

[0139] The present embodiment provides a cylindrical battery cell 20, comprising a housing 21 and an electrode assembly 22, wherein the electrode assembly 22 is housed within the housing 21. The electrode assembly 22 comprises a body 221 and a tab 222. The body 221 is provided with tabs 222 at opposite ends, one being a positive tab 222a and the other being a negative tab 222b. The tab end faces 2221 of the two tabs 222 are each provided with a guide groove 2222. Along the radial direction of the electrode assembly 22, one end of the guide groove 2222 communicates with the center hole 223 of the electrode assembly 22, while the other end of the guide groove 2222 extends through the edge 2223 of the tab. The guide groove 2222 can guide the electrolyte on the periphery of the electrode assembly 22 to the central hole 223, or the electrolyte in the central hole 223 can diffuse to the surrounding through the guide groove 2222, which is conducive to the electrode assembly 22 being fully infiltrated by the electrolyte, so that the cylindrical battery cell 20 has good cycle performance and reduces the risk of lithium plating of the cylindrical battery cell 20, thereby improving the performance of the cylindrical battery cell 20.

[0140] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. An electrode assembly, characterized in that: include: Body part; as well as a tab portion, disposed at one end of the main body portion, the tab portion having a tab end surface disposed away from the main body portion; a center hole, wherein a portion of the center hole is formed in the body portion; In which, the pole ear portion is provided with a guide groove which is recessed from the pole ear end surface toward the direction close to the main body portion, and the guide groove is used to guide the electrolyte to diffuse around the main body portion. The minimum width of the guide groove is smaller than the aperture of the center hole, and the side wall of the guide groove is an arc surface.

2. The electrode assembly according to claim 1, wherein The guide groove is formed by pressing the end surface of the pole lug.

3. The electrode assembly according to claim 1, wherein: The central hole passes through the end surface of the tab, and the guide groove is communicated with the central hole.

4. The electrode assembly according to claim 3, characterized in that The guide groove passes through the edge of the pole lug portion in a direction perpendicular to the axis of the central hole and in a direction away from the axis of the central hole.

5. The electrode assembly according to claim 3, characterized in that The width of the guide groove gradually increases in a direction perpendicular to the axis of the central hole and in a direction away from the axis of the central hole.

6. The electrode assembly according to any one of claims 3 to 5, characterized in that: The guide groove is a groove of equal width.

7. The electrode assembly according to claim 6, characterized in that The width of the guide groove is greater than the diameter of the central hole.

8. The electrode assembly according to any one of claims 3 to 5, characterized in that: A plurality of guide grooves are formed on the end surface of the tab, and the plurality of guide grooves are arranged at intervals around the central hole.

9. The electrode assembly according to claim 8, characterized in that The plurality of guide grooves are evenly spaced around the central hole.

10. A battery cell, characterized in that: include: The electrode assembly according to any one of claims 1 to 9; The shell is used to accommodate the electrode assembly, and the shell has an electrode output portion, and the electrode output portion is used to be connected to the end face of the electrode tab.

11. The battery cell according to claim 10, characterized in that The battery cell further comprises: A current collecting component is accommodated in the shell, the current collecting component abuts against the end surface of the electrode tab, and the current collecting component is connected to the electrode output portion.

12. The battery cell according to claim 11, characterized in that The tab end surface is welded to the current collecting member to form a weld mark on the tab end surface that extends in a radial direction or a circumferential direction of the electrode assembly.

13. A battery, characterized in that: The battery cell comprises the battery cell according to any one of claims 10 to 12.

14. An electrical device, characterized in that: Comprising a battery according to claim 13.

15. A manufacturing device for an electrode assembly, characterized in that: include: Providing an apparatus configured to provide an electrode assembly, the electrode assembly comprising a body portion, a tab portion, and a central hole, the tab portion being disposed at one end of the body portion, the tab portion having a tab end surface disposed away from the body portion, and a portion of the central hole being formed in the body portion; The piercing device is configured to pierce the end face of the pole ear to form a guide groove in the pole ear portion that is recessed from the end face of the pole ear toward the main body portion, and the guide groove is used to guide the electrolyte to diffuse around the main body portion. The minimum width of the guide groove is smaller than the aperture of the center hole, and the side wall of the guide groove is an arc surface.

16. A method for manufacturing an electrode assembly, characterized in that: include: An electrode assembly is provided, the electrode assembly comprising a body portion, a tab portion, and a center hole, the tab portion being disposed at one end of the body portion, the tab portion having a tab end surface disposed away from the body portion, and a portion of the center hole being formed in the body portion; The end face of the pole ear is pierced to form a guide groove in the pole ear portion, which is recessed from the end face of the pole ear toward the main body portion. The guide groove is used to guide the electrolyte to diffuse around the main body portion. The minimum width of the guide groove is smaller than the aperture of the center hole, and the side wall of the guide groove is an arc surface.

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