Battery cell, battery device, and electric device

Abstract

The utility model provides a battery monomer, a battery device and a power utilization device. The battery cell includes an electrode assembly and an electrode terminal. The electrode assembly includes a main body portion, a tab, and an insulating coating layer. And the tabs are positioned outside the main body part. The tab includes a top portion and a root portion. The top is away from the body. The root part is close to the main body part; the root part is connected to the main body part. The tab comprises a first surface and a second surface which are oppositely arranged along the thickness direction of the tab. At least one of the first surface and the second surface is provided with an insulating coating layer. The tab is connected to the electrode terminal and forms a connection portion. The first surface faces the electrode terminal, and the second surface faces away from the electrode terminal.

Description

Technical Field

[0001] This application relates to the field of batteries, and in particular to a battery cell, a battery device, and an electrical device. Background Technology

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development. Improving battery safety has always been a key research direction in battery technology development. Utility Model Content

[0003] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device, which can help improve the safety of the battery device.

[0004] This application provides a battery cell, which includes an electrode assembly and electrode terminals.

[0005] The electrode assembly includes a main body, a tab, and an insulating coating. The tab is located outside the main body. The tab includes a top and a root. The top is away from the main body. The root is close to the main body. The root is connected to the main body. The tab includes a first surface and a second surface disposed opposite to each other along its own thickness direction. At least one of the first surface and the second surface is provided with the insulating coating. The tab is connected to an electrode terminal and forms a connection portion. The first surface faces the electrode terminal, and the second surface faces away from the electrode terminal.

[0006] In the battery cell of this application embodiment, the tabs of the electrode assembly are electrically connected to the electrode terminals. An insulating coating layer is directly formed on at least one of the first and second surfaces of the tab. The method of directly forming the insulating coating layer on the surface of the tab using an insulating material results in a relatively small thickness of the insulating coating layer itself, which helps to reduce the overall thickness of the structure formed by the tab and the insulating coating layer, thereby improving the energy density of the battery cell. The insulating coating layer has strong adhesion to the tab, thus exhibiting strong resistance to electrolyte immersion, which helps to reduce the possibility of the insulating coating layer peeling off due to electrolyte immersion, and helps to meet the insulation requirements throughout the battery cell's lifespan. The method of directly forming the insulating coating layer on the surface of the tab using an insulating material makes it less likely that the insulating coating layer will exert a pulling force on the spacers between the electrodes in the electrode assembly, thereby reducing the possibility of interlayer gaps between different electrodes caused by pulling the spacers during tab folding. The insulating coating can provide insulation and isolation for the tabs, and can cover metal dust or particles to fix the metal dust or particles, reduce the possibility of metal dust or particles falling off, reduce the possibility of short circuit between the positive and negative electrodes caused by the falling metal dust or particles electrically connecting the positive and negative electrodes, improve the safety of the battery cell, and improve the safety of the battery device including the battery cell of the embodiment of this application.

[0007] In some feasible ways, the thickness of the insulating coating gradually increases from the top to the root.

[0008] The thickness of the insulating coating is gradually varied. On the one hand, this helps to reduce the amount of insulating material used and lower production costs while meeting the insulation performance requirements. On the other hand, the thickness of the insulating coating is relatively smaller closer to the top of the electrode, so that the overall thickness of the top area near the electrode and the insulating coating is relatively small, which helps to reduce the bending internal stress in the top area near the electrode.

[0009] In some feasible implementations, the tab includes a first edge and a second edge opposite each other along its own width direction, and the thickness of the insulating coating gradually increases from the first edge to the second edge or from the second edge to the first edge.

[0010] The insulating coating layer has a non-uniform thickness structure. The thickness of the insulating coating layer is gradually varied, which helps to reduce the amount of insulating material used and lower production costs while meeting insulation performance requirements.

[0011] In some feasible implementations, the surface of the insulating coating facing away from the tab includes concave and convex surfaces, with a smooth transition between the concave and convex surfaces.

[0012] The insulating coating layer has a non-uniform thickness structure. The surface flatness requirement of the insulating coating layer facing away from the electrode tab is relatively low. Therefore, when the insulating coating layer is directly formed on the electrode tab using a coating process, the difficulty of the coating process can be reduced, which is conducive to improving work efficiency.

[0013] In some feasible methods, the maximum thickness of the insulating coating is less than or equal to 30 micrometers, and the minimum thickness is greater than or equal to 10 micrometers.

[0014] If the minimum thickness of the insulating coating is less than 10 micrometers, there are areas where the coating is too thin, leading to deviations in its wear resistance and insulation performance. If the maximum thickness of the insulating coating is greater than 30 micrometers, there are areas where the coating is too thick, resulting in the use of more insulating material, increasing production costs, and increasing the overall weight of the coating, thus reducing the energy density of the battery cell. The method of using a maximum thickness of 30 micrometers or less and a minimum thickness of 10 micrometers or more in the insulating coating embodiments of this application helps to solve the above-mentioned technical problems.

[0015] In some feasible methods, the insulating coating layer is a layer structure of uniform thickness.

[0016] The thickness of the insulating coating can be the same at different locations. This allows the insulating coating to maintain relatively consistent insulation performance across its various locations, which helps ensure a consistent insulation effect on the tabs.

[0017] In some feasible methods, the thickness of the insulating coating ranges from 10 micrometers to 30 micrometers.

[0018] In some feasible embodiments, an insulating coating is provided on both the first and second surfaces, with the insulating coating on the first surface avoiding the connection portion and the insulating coating on the second surface covering the connection portion.

[0019] During the process of connecting the tabs and electrode terminals to form a connection, there is a possibility of metal powder or particles forming on the connection. The insulating coating can provide insulation and isolation for the connection, and can also cover the metal dust or particles present on the connection, thereby fixing the metal dust or particles, reducing the possibility of metal dust or particles falling off, and reducing the possibility of short circuits between the positive and negative electrode plates caused by falling metal dust or particles electrically connecting the positive and negative electrode plates, thus improving the safety of the battery cell.

[0020] In some possible implementations, the first surface includes a first region and a second region, the first region being disposed corresponding to the connection portion, the second region being disposed surrounding the first region, an insulating coating layer located on the first surface covering the entire second region, and an insulating coating layer located on the second surface covering the entire second surface.

[0021] For the first surface of the electrode, except for the first area corresponding to the connecting portion, an insulating coating layer is provided on all other areas to improve the insulation effect of the insulating coating layer on the first surface of the electrode. An insulating coating layer is provided on all areas of the second surface of the electrode to improve the insulation effect of the insulating coating layer on the second surface of the electrode.

[0022] In some feasible embodiments, the battery cell also includes a housing and an end cap, with the end cap connected to the housing, the main body disposed within the housing, and the electrode terminals disposed on the end cap.

[0023] This application provides a battery device that includes the aforementioned battery cell.

[0024] This application provides an electrical device including the battery device described above. The battery device is used to provide electrical energy. Attached Figure Description

[0025] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0026] Figure 1 This is a schematic diagram of the structure of a vehicle provided in one embodiment of this application;

[0027] Figure 2 This is a partially exploded structural diagram of a battery device provided in an embodiment of this application;

[0028] Figure 3 This is a schematic diagram of the structure of a battery module provided in one embodiment of the application;

[0029] Figure 4 This is a partially exploded structural diagram of a battery cell provided in an embodiment of this application;

[0030] Figure 5 This is a partial structural schematic diagram of a battery cell provided in an embodiment of this application;

[0031] Figure 6 This is a partial structural schematic diagram of a battery cell provided in an embodiment of this application;

[0032] Figure 7 This is a partial structural schematic diagram of an electrode assembly provided in an embodiment of this application;

[0033] Figure 8 This is a partial structural schematic diagram of an electrode assembly provided in an embodiment of this application;

[0034] Figure 9This is a partially exploded structural diagram of an electrode assembly provided in an embodiment of this application;

[0035] Figure 10 This is a partially exploded structural diagram of an electrode assembly provided in an embodiment of this application;

[0036] Figure 11 This is a partial structural schematic diagram of an electrode assembly provided in an embodiment of this application;

[0037] Figure 12 This is a partially exploded structural diagram of an electrode assembly provided in an embodiment of this application;

[0038] Figure 13 This is a partial structural schematic diagram of a battery cell provided in an embodiment of this application;

[0039] Figure 14 This is a partial structural schematic diagram of a battery cell provided in an embodiment of this application.

[0040] Explanation of reference numerals in the attached figures:

[0041] 1. Vehicle; 10. Battery assembly; 10a. Housing; 10b. First housing section; 10c. Second housing section;

[0042] 11. Controller; 12. Motor;

[0043] 20. Battery module;

[0044] 30. Battery cell;

[0045] 40. End cap; 41. Electrode terminal;

[0046] 50. Shell;

[0047] 60. Electrode assembly; 61. Main body; 62. Tab; 62a. First surface; 62b. Second surface; 62c. First region; 62d. Second region; 621. Top; 622. Root; 623. First edge; 624. Second edge;

[0048] 70. Insulating coating layer; 71. Concave surface; 72. Convex surface;

[0049] 100. Connecting part;

[0050] X, width direction. Detailed Implementation

[0051] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0052] It should be noted that, unless otherwise stated, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by those skilled in the art to which the embodiments of this application pertain.

[0053] In the description of the embodiments of this application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0054] Furthermore, technical terms such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of the embodiments of this application, "a plurality of" means two or more, unless otherwise explicitly defined.

[0055] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0056] In the description of the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0057] Currently, judging from market trends, the application of battery devices is becoming increasingly widespread. Battery devices are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely applied in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery device applications, market demand is also constantly increasing.

[0058] In this application, the battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, etc., and the embodiments of this application are not limited thereto. The battery cell may be flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited thereto.

[0059] The battery device mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity. The battery device mentioned in this application can be a battery pack. For example, the battery device mentioned in this application can include battery modules, etc. A battery device generally includes a housing for encapsulating one or more battery cells. The housing can prevent liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0060] A single battery cell includes an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode, a negative electrode, and a separator. The electrode assembly also includes a main body and tabs. The tabs extend from the main body. The battery cell primarily functions by the movement of metal ions between the positive and negative electrode plates.

[0061] The positive electrode includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector. The positive current collector includes a positive current collection section and a positive electrode tab connected to the current collection section. The positive current collection section is coated with the positive active material layer. The positive electrode tab is not coated with the positive active material layer. Taking a lithium-ion battery as an example, the material of the positive current collector can be aluminum. The positive active material layer includes the positive active material. The positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc.

[0062] 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 negative electrode current collector includes a negative electrode current collection section and a negative electrode tab connected to the negative electrode current collection section. The negative electrode current collection section is coated with the negative electrode active material layer. The negative electrode tab is not coated with the negative electrode active material layer. The material of the negative electrode current collector can be copper. The negative electrode active material layer includes the negative electrode active material. The negative electrode active material can be carbon or silicon, etc.

[0063] The material of the separator can be PP (polypropylene) or PE (polyethylene), etc.

[0064] The tabs of the electrode assembly need to be shaped and trimmed through a cutting process. The tabs are made of metal, such as copper or aluminum. During the cutting process, metal dust or particles may remain on the surface of the tabs. When this metal dust or particles fall into the battery cell, they can electrically connect the positive and negative electrodes, causing a short circuit. In the event of a short circuit between the positive and negative electrodes, the battery cell may experience thermal runaway.

[0065] To alleviate the problem of metal dust or particles remaining on the surface of the electrode and falling off, the surface of the electrode can be insulated. This allows the insulating material to provide insulation and isolation for the electrode, and when there is metal dust or particles remaining on the surface of the electrode, the metal dust or particles are fixed by the insulating material, reducing the possibility of metal dust or particles falling off.

[0066] Based on the above considerations, to alleviate the problem of metal dust or particle residue on the electrode surface and subsequent falling off, the inventors, after in-depth research, designed a new battery cell. In this battery cell, an insulating coating layer is directly disposed on the electrode tabs of the electrode assembly. The insulating coating layer is attached to the surface of the electrode tabs. The insulating coating layer can provide insulation and isolation for the electrode tabs. When metal dust or particle residue exists on the electrode tab surface, the insulating coating layer can cover the metal dust or particles, thereby fixing the metal dust or particles, reducing the possibility of metal dust or particles falling off, and reducing the possibility of short circuits between the positive and negative electrode plates caused by the falling metal dust or particles electrically connecting the positive and negative electrode plates, thus improving the safety of the battery cell.

[0067] The technical solutions described in the embodiments of this application are applicable to battery devices and electrical devices that use battery devices.

[0068] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles. Spacecraft include airplanes, rockets, space shuttles, and spacecraft. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers. This application does not impose any special limitations on the above-mentioned electrical devices.

[0069] It should be understood that the technical solutions described in the embodiments of this application are not limited to the battery devices and electrical devices described above, but can also be applied to all battery devices including housings and electrical devices using battery devices. However, for the sake of brevity, the following embodiments are all illustrated using electric vehicles as examples.

[0070] Figure 1 The structure of vehicle 1 is shown schematically. See also Figure 1 As shown, vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 10 is installed inside vehicle 1. The battery device 10 can be located at the bottom, front, or rear of vehicle 1. The battery device 10 can be used to power vehicle 1. For example, the battery device 10 can serve as the operating power source for vehicle 1. Vehicle 1 may also include a controller 11 and a motor 12. The controller 11 is used to control the battery device 10 to supply power to the motor 12. For example, this is for the power needs of vehicle 1 during starting, navigation, and driving.

[0071] In some embodiments of this application, the battery device 10 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, to replace or partially replace fuel or natural gas to provide driving power for the vehicle 1.

[0072] To meet different power demands, the battery device 10 may include multiple battery cells. A battery cell is the smallest unit that makes up a battery module or battery pack. Multiple battery cells can be connected in series and / or in parallel via electrode terminals for various applications. The battery device mentioned in this application includes a battery module or battery pack. Multiple battery cells can be connected in series, in parallel, or in a mixed configuration. A mixed configuration refers to a combination of series and parallel connections. In the embodiments of this application, multiple battery cells can be directly assembled into a battery pack, or they can first be assembled into a battery module 20, and then the battery module 20 can be assembled into a battery pack.

[0073] Figure 2 A partial exploded view of the battery assembly 10 is schematically shown. See also... Figure 2 As shown, the battery device 10 includes a housing 10a and individual battery cells (not shown). The individual battery cells are housed within the housing 10a.

[0074] The housing 10a can be a simple three-dimensional structure such as a single cuboid, cylinder, or sphere, or it can be a complex three-dimensional structure composed of simple three-dimensional structures such as cuboids, cylinders, or spheres. This application embodiment does not limit this. The material of the housing 10a can be an alloy material such as aluminum alloy or iron alloy, or a polymer material such as polycarbonate or polyisocyanurate foam, or a composite material such as glass fiber and epoxy resin. This application embodiment also does not limit this.

[0075] The housing 10a is used to accommodate individual battery cells, and the housing 10a can have various structures. In some embodiments, the housing 10a may include a first housing portion 10b and a second housing portion 10c. The first housing portion 10b and the second housing portion 10c overlap each other. The first housing portion 10b and the second housing portion 10c together define a receiving space for accommodating the individual battery cells. The second housing portion 10c may be a hollow structure with one open end. In some embodiments, the first housing portion 10b is a plate-like structure. The first housing portion 10b overlaps the open side of the second housing portion 10c to form a housing 10a with a receiving space. In some embodiments, both the first housing portion 10b and the second housing portion 10c may also be hollow structures with one open side. The open side of the first housing portion 10b overlaps the open side of the second housing portion 10c to form a housing 10a with a receiving space. Of course, the first housing portion 10b and the second housing portion 10c can have various shapes, such as cylinders, cuboids, etc.

[0076] To improve the sealing performance after the first housing part 10b and the second housing part 10c are connected, a sealing element, such as sealant or sealing ring, can also be provided between the first housing part 10b and the second housing part 10c.

[0077] In some embodiments, the first housing portion 10b covers the top of the second housing portion 10c. The first housing portion 10b may also be referred to as the upper housing cover, and the second housing portion 10c may also be referred to as the lower housing.

[0078] In the battery device 10, there can be one or more battery cells. When there are multiple battery cells, they can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells are connected in both series and parallel. Multiple battery cells can be directly connected in series, parallel, or in a mixed configuration and then housed within the housing 10a. Alternatively, multiple battery cells can first be connected in series, parallel, or in a mixed configuration to form a battery module. Multiple battery modules can then be connected in series, parallel, or in a mixed configuration to form a whole and housed within the housing 10a.

[0079] In some embodiments, Figure 3 The structure of battery module 20 is shown schematically. See also Figure 3 As shown, there can be multiple battery cells 30. Multiple battery cells 30 are first connected in series, parallel, or in a mixed connection to form a battery module 20. Multiple battery modules 20 are then connected in series, parallel, or in a mixed connection to form a whole, which is housed in the casing 10a.

[0080] Multiple battery cells 30 in the battery module 20 can be electrically connected through a busbar component to achieve parallel, series, or mixed connection of multiple battery cells 30 in the battery module 20.

[0081] In this embodiment, the battery cell 30 may include a lithium-ion battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, etc., and this embodiment is not limited thereto. The battery cell 30 may be flat, cuboid, or other shapes, and this embodiment is not limited thereto either. However, for the sake of brevity, the following embodiment uses a cuboid battery cell 30 as an example for illustration.

[0082] Figure 4 The diagram schematically shows a partially disassembled structure of the battery cell 30. The battery cell 30 refers to the smallest unit comprising the battery assembly 10. See also... Figure 4 As shown, the battery cell 30 includes an end cap 40, a housing 50, and an electrode assembly 60.

[0083] End cap 40 refers to a component that covers the opening of housing 50 to isolate the internal environment of battery cell 30 from the external environment. Exemplarily, the shape of end cap 40 can be adapted to the shape of housing 50 to fit the housing 50. Exemplarily, end cap 40 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that end cap 40 is not easily deformed under pressure or impact, enabling battery cell 30 to have higher structural strength and improved safety performance. Functional components such as electrode terminals 41 can be provided on end cap 40. Electrode terminals 41 can be used for electrical connection with electrode assembly 60 for outputting or inputting electrical energy into battery cell 30.

[0084] In some embodiments, the end cap 40 may also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of the battery cell 30 reaches a threshold. The end cap 40 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this. In some embodiments, an insulating component may also be provided on the inner side of the end cap 40. The insulating component can be used to isolate the electrical connection components within the housing 50 from the end cap 40 to reduce the risk of short circuits. Exemplarily, the insulating component can be plastic, rubber, etc.

[0085] The housing 50 is a component used to cooperate with the end cap 40 to form the internal environment of the battery cell 30. The formed internal environment can accommodate the electrode assembly 60, electrolyte (not shown in the figure), and other components. The housing 50 and the end cap 40 can be independent components. An opening can be provided on the housing 50, and the end cap 40 closes the opening to form the internal environment of the battery cell 30. Alternatively, the end cap 40 and the housing 50 can be integrated. Specifically, the end cap 40 and the housing 50 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 50, the end cap 40 closes the housing 50. The housing 50 can be of various shapes and sizes, such as cuboid, hexagonal prism, etc. Specifically, the shape of the housing 50 can be determined according to the specific shape and size of the electrode assembly 60. The material of the housing 50 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment does not impose any special limitations on this.

[0086] Electrode assembly 60 is the component in the battery cell 30 where electrochemical reactions occur. The housing 50 may contain one or more electrode assemblies 60. Electrode assembly 60 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body of the electrode assembly. The portions of the positive and negative electrode sheets without active material each constitute a tab (not shown in the figure). The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of the battery, the positive and negative active materials react with the electrolyte, and the tabs connect to the electrode terminals 41 to form a current loop.

[0087] Figure 5 A partial structure of the battery cell 30 is shown schematically. Figure 6 A partial structure of the battery cell 30 is shown schematically. Figure 7 A partial structure of the electrode assembly 60 is shown schematically. See also Figure 5 , Figure 6 and Figure 7As shown, this application embodiment provides a battery cell 30, which includes an electrode assembly 60 and an electrode terminal 41. The electrode assembly 60 includes a main body 61, a tab 62, and an insulating coating layer 70. The tab 62 is located outside the main body 61. The tab 62 includes a top 621 and a root 622. The top 621 is away from the main body 61. The root 622 is close to the main body 61. The root 622 is connected to the main body 61. The tab 62 includes a first surface 62a and a second surface 62b disposed opposite each other along its own thickness direction. At least one of the first surface 62a and the second surface 62b of the tab 62 is provided with the insulating coating layer 70. The tab 62 is connected to the electrode terminal 41 and forms a connection portion 100. The first surface 62a faces the electrode terminal 41. The second surface 62b faces away from the electrode terminal 41.

[0088] In this embodiment, the tab 62 extends from the main body 61. Before the tab 62 is connected to the electrode terminal 41, the top 621 of the tab 62 is in a free state. The electrode assembly 60 is electrically connected to the electrode terminal 41 via the tab 62. After the tab 62 is electrically connected to the electrode terminal 41, an insulating coating layer 70 is formed on the tab 62. In some feasible embodiments, insulating material can be sprayed onto the tab 62 using a spraying process. The insulating material is then molded to form the insulating coating layer 70. In some feasible embodiments, the insulating material includes, but is not limited to, polyurethane insulating varnish, epoxy resin insulating varnish, silicone rubber insulating varnish, acrylic insulating varnish, ceramic insulating varnish, and nanocomposite material insulating varnish. The insulating material has good chemical stability and corrosion resistance and is not easily reactive with the electrolyte. By directly forming the insulating coating layer 70 on the tab 62 with insulating material, the insulating coating layer 70 has high adhesion to the surface of the tab 62, making it difficult for the insulating coating layer 70 to separate or fall off from the tab 62.

[0089] In the battery cell 30 of this application embodiment, the tab 62 of the electrode assembly 60 is electrically connected to the electrode terminal 41. An insulating coating layer 70 is directly disposed on at least one of the first surface 62a and the second surface 62b of the tab 62. By directly forming the insulating coating layer 70 on the surface of the tab 62 using an insulating material, the thickness of the insulating coating layer 70 itself is relatively small, which helps to reduce the thickness of the overall structure formed by the tab 62 and the insulating coating layer 70, thereby helping to improve the energy density of the battery cell 30. The insulating coating layer 70 has strong adhesion to the tab 62, so the insulating coating layer 70 has strong resistance to electrolyte immersion, which helps to reduce the possibility of the insulating coating layer 70 falling off due to electrolyte immersion, and helps to meet the insulation requirements of the battery cell 30 throughout its service life. By directly forming the insulating coating layer 70 on the surface of the tab 62 using an insulating material, the insulating coating layer 70 is less likely to exert a pulling force on the spacer between the electrodes in the electrode assembly 60, thereby reducing the possibility of interlayer gaps between different electrodes caused by pulling the spacer during the folding of the tab 62. The insulating coating layer 70 can provide insulation and isolation for the tab 62, and can cover metal dust or particles to fix the metal dust or particles, reduce the possibility of metal dust or particles falling off, reduce the possibility of short circuit between the positive and negative electrode plates caused by falling metal dust or particles electrically connecting the positive and negative electrode plates, and improve the safety of the battery cell 30.

[0090] In some feasible ways, Figure 8 A partial structure of the electrode assembly 60 is shown schematically. See also Figure 8 As shown, the thickness of the insulating coating layer 70 gradually increases from the top 621 to the root 622 of the tab 62. The insulating coating layer 70 has a non-uniform thickness structure. The thickness of the insulating coating layer 70 adopts a gradual approach. On the one hand, this helps to reduce the amount of insulating material used and lower production costs while meeting insulation performance requirements. On the other hand, the thickness of the insulating coating layer 70 is relatively smaller closer to the top 621 of the tab 62, resulting in a relatively smaller overall thickness formed by the region near the top 621 of the tab 62 and the insulating coating layer 70. This helps to reduce the bending internal stress in the region near the top 621 of the tab 62.

[0091] In some examples, the surface of the insulating coating 70 facing away from the tab 62 can be a flat surface.

[0092] In some examples, the maximum thickness of the insulating coating 70 is less than or equal to 30 micrometers (μm), and the minimum thickness is greater than or equal to 10 micrometers. For example, the maximum thickness of the insulating coating 70 is equal to 25 micrometers, and the minimum thickness is equal to 15 micrometers. Alternatively, the maximum thickness of the insulating coating 70 is equal to 20 micrometers, and the minimum thickness is equal to 12 micrometers.

[0093] If the minimum thickness of the insulating coating layer 70 is less than 10 micrometers, there are areas where the thickness of the insulating coating layer 70 is too small, resulting in deviations in the wear resistance and insulation performance of the insulating coating layer 70. If the maximum thickness of the insulating coating layer 70 is greater than 30 micrometers, there are areas where the thickness of the insulating coating layer 70 is too large, resulting in the use of more insulating material, increasing production costs, and increasing the overall weight of the insulating coating layer 70, leading to a decrease in the energy density of the battery cell 30. The method of the insulating coating layer 70 in the embodiments of this application, with a maximum thickness of less than or equal to 30 micrometers and a minimum thickness of greater than or equal to 10 micrometers, is beneficial to solving the above-mentioned technical problems.

[0094] In related technologies, adhesive tape is used to insulate the tab 62. The tape itself is relatively thick, resulting in a relatively large overall thickness formed by the tab 62 and the tape, which affects the energy density of the battery cell 30. In this embodiment, the insulating coating layer 70 has a relatively small thickness. The maximum thickness of the insulating coating layer 70 can be less than the thickness of the tape, which helps reduce the overall thickness of the structure formed by the tab 62 and the insulating coating layer 70, thereby improving the energy density of the battery cell 30.

[0095] In some feasible ways, Figure 9 A partial exploded view of the electrode assembly 60 is schematically shown. Figure 10 A partial exploded view of the electrode assembly 60 is schematically shown. See also Figure 9 and Figure 10 As shown, the tab 62 includes a first edge 623 and a second edge 624 opposite to each other along its width direction X. The thickness of the insulating coating layer 70 gradually increases from the first edge 623 to the second edge 624 or from the second edge 624 to the first edge 623.

[0096] The insulating coating layer 70 has a non-uniform thickness structure. The thickness of the insulating coating layer 70 is gradually varied, which helps to reduce the amount of insulating material used and lower production costs while meeting insulation performance requirements.

[0097] In some examples, the surface of the insulating coating 70 facing away from the tab 62 can be a flat surface.

[0098] In some examples, the maximum thickness of the insulating coating 70 is less than or equal to 30 micrometers (μm), and the minimum thickness is greater than or equal to 10 micrometers. For example, the maximum thickness of the insulating coating 70 is equal to 25 micrometers, and the minimum thickness is equal to 15 micrometers. Alternatively, the maximum thickness of the insulating coating 70 is equal to 20 micrometers, and the minimum thickness is equal to 12 micrometers.

[0099] In some possible implementations, the thickness of the insulating coating 70 gradually increases from the top 621 of the tab 62 to the root 622, and from the first edge 623 to the second edge 624 or from the second edge 624 to the first edge 623.

[0100] In some feasible ways, Figure 11 A partial structure of the electrode assembly 60 is shown schematically. See also Figure 11 As shown, the surface of the insulating coating layer 70 facing away from the tab 62 includes a concave surface 71 and a convex surface 72. There is a smooth transition between the concave surface 71 and the convex surface 72. There are no sharp transition areas between the concave surface 71 and the convex surface 72. Both the concave surface 71 and the convex surface 72 can be curved surfaces. The insulating coating layer 70 has a non-uniform thickness structure. The surface flatness requirement for the insulating coating layer 70 facing away from the tab 62 is relatively low. Therefore, when the insulating coating layer 70 is directly formed on the tab 62 using a coating process, the difficulty of the coating process can be reduced, which is beneficial to improving work efficiency.

[0101] In some examples, an insulating coating layer 70 is directly formed on the tab 62 using a spraying process.

[0102] In some examples, the maximum thickness of the insulating coating 70 is less than or equal to 30 micrometers, and the minimum thickness is greater than or equal to 10 micrometers. For example, the maximum thickness of the insulating coating 70 is equal to 25 micrometers, and the minimum thickness is equal to 15 micrometers. Alternatively, the maximum thickness of the insulating coating 70 is equal to 20 micrometers, and the minimum thickness is equal to 12 micrometers.

[0103] In some feasible implementations, the insulating coating layer 70 has a uniform thickness structure. The thickness of the insulating coating layer 70 can be the same at different locations. The insulating coating layer 70 can maintain relatively consistent insulation performance at different locations, which helps to ensure that the insulating coating layer 70 provides consistent insulation to the tab 62.

[0104] In some examples, the thickness of the insulating coating 70 ranges from 10 micrometers to 30 micrometers. For example, the thickness of the insulating coating 70 can be equal to 12 micrometers, 15 micrometers, 20 micrometers, or 25 micrometers.

[0105] In some possible implementations, both the first surface 62a and the second surface 62b of the tab 62 are provided with an insulating coating layer 70. The insulating coating layer 70 on the first surface 62a avoids the connecting portion 100. The insulating coating layer 70 on the second surface 62b covers the connecting portion 100.

[0106] During the process of connecting the tab 62 and the electrode terminal 41 to form the connection portion 100, there is a possibility that metal powder or particles may form on the connection portion 100. The insulating coating layer 70 can provide insulation and isolation for the connection portion 100, and can also cover the metal dust or particles present on the connection portion 100 to fix the metal dust or particles, reduce the possibility of metal dust or particles falling off, reduce the possibility of short circuit between the positive and negative electrode plates caused by the falling metal dust or particles electrically connecting the positive and negative electrode plates, and improve the safety of the battery cell 30.

[0107] The insulating coating layer 70 of the first surface 62a avoids the connection portion 100, so as to reduce the possibility that the actual connection area between the tab 62 and the electrode terminal 41 will be reduced due to the overlap between the insulating coating layer 70 and the connection portion 100, thus affecting the electrical connection performance between the tab 62 and the electrode terminal 41.

[0108] In some examples, the tab 62 and the electrode terminal 41 can be connected by welding to form a connection portion 100. Exemplarily, the tab 62 and the electrode terminal 41 are connected by laser welding.

[0109] In some feasible ways, Figure 12 A partial exploded view of the electrode assembly 60 is schematically shown. See also Figure 12 As shown, the first surface 62a of the tab 62 includes a first region 62c and a second region 62d. The first region 62c is disposed corresponding to the connecting portion 100. The second region 62d is disposed around the first region 62c. An insulating coating layer 70 located on the first surface 62a covers the entire second region 62d. An insulating coating layer 70 located on the second surface 62b covers the entire second surface 62b.

[0110] For the first surface 62a of the tab 62, except for the first region 62c corresponding to the connecting portion 100, an insulating coating layer 70 is provided on all other regions to improve the insulation effect of the insulating coating layer 70 on the first surface 62a of the tab 62. An insulating coating layer 70 is provided on all regions of the second surface 62b of the tab 62 to improve the insulation effect of the insulating coating layer 70 on the second surface 62b of the tab 62.

[0111] In some examples, tab 62 includes a top 621, a root 622, a first edge 623, and a second edge 624. The insulating coating 70 does not extend beyond the edges of the first edge 623, the second edge 624, and the top 621 of tab 62.

[0112] In some implementations, the battery cell 30 also includes a housing 50 and an end cap 40. The end cap 40 is connected to the housing 50. The main body 61 of the electrode assembly 60 is disposed within the housing 50. Electrode terminals 41 are disposed on the end cap 40. The housing 50 and the end cap 40 are connected and fitted to form an internal environment for accommodating the electrode assembly 60 and the electrolyte.

[0113] In some examples, a portion of the first surface 62a of the tab 62 faces the housing 50. A portion of the second surface 62b of the tab 62 faces away from the housing 50.

[0114] See in some examples Figure 5 and Figure 6 As shown, the battery cell 30 includes an electrode assembly 60. Figure 5 and Figure 6 In the initial configuration, the electrode assembly 60 and end cap 40 are laid flat. Before inserting them into the housing 50, the electrode assembly 60 needs to be flipped relative to the end cap 40. Then, the electrode assembly 60 is inserted into the housing 50.

[0115] In some examples, Figure 13 A partial structure of the battery cell 30 is shown schematically. Figure 14 A partial structure of the battery cell 30 is schematically shown. See also Figure 13 and Figure 14 As shown, the battery cell 30 includes two electrode assemblies 60. The tabs 62 of the two electrode assemblies 60 are electrically connected to the corresponding electrode terminals 41. Figure 13 and Figure 14 In the first case, the electrode assembly 60 and the end cap 40 are laid flat. Before inserting them into the housing 50, the two electrode assemblies 60 need to be flipped relative to the end cap 40 so that the two electrode assemblies 60 are in contact with each other. Then, the two electrode assemblies 60 are inserted into the housing 50.

[0116] According to some embodiments of this application, this application also provides a battery device 10, including a battery cell 30 of any of the above schemes.

[0117] According to some embodiments of this application, this application also provides an electrical device including a battery device 10 of any of the above schemes, and the battery device 10 is used to provide electrical energy to the electrical device.

[0118] The power supply device can be any of the aforementioned devices or systems that utilize battery device 10.

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized by, The battery monomer comprises: an electrode assembly comprising a main body, a tab, and an insulating coating layer, the tab being located outside the main body, the tab comprising a top portion and a root portion, the top portion being away from the main body, the root portion being close to the main body, the root portion being connected to the main body, the tab comprising a first surface and a second surface oppositely arranged along a thickness direction of the tab, at least one of the first surface and the second surface being provided with the insulating coating layer; an electrode terminal, the tab being connected to the electrode terminal and forming a connecting portion, the first surface facing the electrode terminal, the second surface facing away from the electrode terminal.

2. The battery cell of claim 1, wherein, The thickness of the insulating coating layer gradually increases from the top portion to the root portion.

3. The battery cell according to claim 1 or 2, characterized in that, The tab comprises a first edge and a second edge oppositely arranged along a width direction of the tab, the thickness of the insulating coating layer gradually increases from the first edge to the second edge or from the second edge to the first edge.

4. The battery cell of claim 1, wherein, The surface of the insulating coating layer facing away from the tab comprises a concave surface and a convex surface, and the concave surface and the convex surface are smoothly connected.

5. The battery cell according to any one of claims 2 to 4, characterized in that, The maximum thickness of the insulating coating layer is less than or equal to 30 microns, and the minimum thickness is greater than or equal to 10 microns.

6. The battery cell of claim 1, wherein, The insulating coating layer is an equal-thickness layer structure.

7. The battery cell of claim 6, wherein, The thickness of the insulating coating layer is in a range of 10 microns to 30 microns.

8. The battery cell of any one of claims 1 to 7, wherein, Both the first surface and the second surface are provided with the insulating coating layer, the insulating coating layer located on the first surface avoids the connecting portion, and the insulating coating layer located on the second surface covers the connecting portion.

9. The battery cell of claim 8, wherein, The first surface comprises a first region and a second region, the first region corresponds to the connecting portion, and the second region is arranged around the first region, the insulating coating layer located on the first surface covers the entire second region, and the insulating coating layer located on the second surface covers the entire second surface.

10. The battery cell of any one of claims 1 to 9, wherein, The battery monomer further comprises a shell and an end cover, the end cover is connected to the shell, the main body is arranged in the shell, and the electrode terminal is arranged in the end cover.

11. A battery device characterized by comprising: The battery device comprises the battery monomer as claimed in any one of claims 1 to 10.

12. An electrical device, characterized by The battery device as claimed in claim 11 is used to provide electric energy.

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