Battery monomer, battery and electric equipment

Abstract

The utility model relates to the technical field of batteries, and provides a battery monomer, a battery and electric equipment, the battery monomer comprises two pole pieces which are stacked; each pole piece comprises a current collector, an active material layer and an electric connecting piece, the current collector is provided with a first edge side and a second edge side, and the electric connecting piece is connected to the first edge side; at least one pole piece further comprises a first insulating layer and a second insulating layer, the first insulating layer and the second insulating layer are arranged on the two opposite sides of the active material layer respectively, the side, away from the active material layer, of the first insulating layer extends towards the first edge side, and the side, away from the active material layer, of the second insulating layer extends towards the second edge side. According to the battery monomer provided by the embodiment of the invention, after the two insulating layers are additionally arranged on the current collector of the pole piece, the performance of the battery monomer is more stable.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and particularly provides a battery cell, a battery and an electrical device. Background Art

[0002] Currently, a battery cell includes a positive electrode plate, a negative electrode plate and a separator formed by winding or laminating. Among them, the electrode plate includes a current collector, an active material layer coated on the current collector, and an electrical connection member electrically connected to the current collector. On the current collector, the area coated with the active material layer is the film area, the area welded to the electrical connection member is the roll welding area, and the transition area between the film area and the roll welding area is the extension area. Usually, the extension area lacks necessary protection, and a large number of particles generated by winding or laminating in the film area and the roll welding area will enter the electrode assembly. Or, when the electrode plate is slit or die-cut, burrs are formed at the edge of the electrode plate, which are likely to pierce the separator and cause internal short circuit of the battery cell. Summary of the Utility Model

[0003] An object of the embodiments of the present application is to provide a battery cell, a battery and an electrical device, aiming to solve the problem that the electrode plate of the existing battery cell is prone to performance defects during the forming process.

[0004] To achieve the above object, the technical solution adopted in the embodiments of the present application is:

[0005] In a first aspect, the embodiments of the present application provide a battery cell, including: two electrode plates arranged in a stacked manner;

[0006] Each of the electrode plates includes a current collector, an active material layer coated on the current collector, and an electrical connection member. The current collector has a first edge side and a second edge side arranged oppositely, and the electrical connection member is connected to the first edge side;

[0007] At least one of the electrode plates further includes a first insulating layer and a second insulating layer. The first insulating layer and the second insulating layer are respectively arranged on opposite sides of the active material layer, and the side of the first insulating layer away from the active material layer extends towards the first edge side, and the side of the second insulating layer away from the active material layer extends towards the second edge side.

[0008] Advantages of the embodiments of the present application: For the battery cell provided in the present application, a first insulating layer and a second insulating layer are provided on opposite sides of the active material layer of at least one electrode tab. The first insulating layer is used to cover and protect the transition region between the active material layer of the current electrode tab and the electrical connection member, reducing the influence of the particles formed during the winding process of the electrode tab on the transition region. At the same time, the second insulating layer at the second edge side of the current electrode tab's current collector can support the active material layer or the electrical connection member of the adjacent electrode tab, thereby reducing the probability of internal short circuit of the battery cell caused by the burrs at the edge of the electrode tab due to slitting or die-cutting. In this way, after adding two insulating layers on the current collector of the electrode tab, the battery cell provided by the embodiments of the present application has more stable performance.

[0009] In some embodiments, the first insulating layer is connected to the active material layer; and / or, the second insulating layer is connected to the active material layer.

[0010] By adopting the above technical solution, the side part of the active material layer is fixed and wrapped by the first insulating layer and / or the second insulating layer, which can effectively reduce the probability of the active material layer cracking or falling off during winding or laminating, and at the same time, can also improve the connection stability of the active material layer on the current collector.

[0011] In some embodiments, the thickness of the first insulating layer is greater than or equal to the thickness of the active material layer; and / or, the thickness of the second insulating layer is greater than or equal to the thickness of the active material layer.

[0012] By adopting the above technical solution, the first insulating layer or the second insulating layer of the current electrode tab can be used to support the first edge side or the second edge side of the adjacent electrode tab, thereby reducing the probability of cracking or short circuit of the end face of the electrode tab caused by extrusion deformation.

[0013] In some embodiments, in the thickness direction of the electrode tab, the projection of the edge side of the first insulating layer coincides with the projection of the edge side of the active material layer; and / or, the projection of the edge side of the second insulating layer coincides with the projection of the edge side of the active material layer.

[0014] By adopting the above technical solution, the first insulating layer and / or the second insulating layer coincide with the active material layer in the coating position, which can further improve the bonding stability at the connection between the insulating layer and the active material layer, and effectively reduce the probability of the active material layer cracking or falling off during winding or laminating.

[0015] In some embodiments, the edge side of the first insulating layer is spaced apart from the edge side of the active material layer; and / or, the edge side of the second insulating layer is spaced apart from the edge side of the active material layer.

[0016] By adopting the above technical solution, a gap is formed between the first insulating layer and / or the second insulating layer and the edge of the active material layer, so as to reduce the risk of fusion and penetration between the insulating layer and the active material layer, which is beneficial to improving the reliability during the use of the battery.

[0017] In some embodiments, one side of the first insulating layer away from the active material layer extends towards the electrical connection member, and is spaced apart from the edge side of the electrical connection member.

[0018] By adopting the above technical solution, a gap is formed between the edge side of the first insulating layer and the edge side of the electrical connection member. Similarly, when the electrode sheet is wound or laminated, the probability of the first insulating layer falling off, delaminating and cracking due to extrusion with the electrical connection member can be reduced.

[0019] In some embodiments, the current collector includes a substrate and conductive layers formed on opposite end faces of the substrate. The active material layer, the first insulating layer and the second insulating layer are all coated on the conductive layer. The electrical connection member includes a main body portion and a branch portion connected to the main body portion. The main body portion is electrically connected to one of the conductive layers, and the branch portion is electrically connected to the other conductive layer.

[0020] By adopting the above technical solution, the current collector is a current collector with a composite structure. Specifically, conductive layers are formed on opposite sides of the substrate, and the conductive layers are used as carriers for coating the active material layer, the first insulating layer and the second insulating layer. Moreover, when the electrical connection member is electrically connected to the current collector, the main body portion and the branch portion can be respectively welded to the corresponding conductive layers.

[0021] In some embodiments, the electrode sheet includes a positive electrode sheet and a negative electrode sheet. In the thickness direction of the electrode sheet;

[0022] The projection of the first edge side of the negative electrode sheet falls within the projection of the second insulating layer of the positive electrode sheet; or,

[0023] The projection of the electrical connection member of the negative electrode sheet falls within the projection of the second insulating layer of the positive electrode sheet;

[0024] The projection of the second edge side of the negative electrode sheet falls within the projection of the first insulating layer of the positive electrode sheet.

[0025] By adopting the above technical solution, when the positive electrode sheet and the negative electrode sheet are wound or laminated, the projection of the first edge side of the negative electrode sheet or the projection of the electrical connection thereon falls within the projection of the second insulating layer of the positive electrode sheet, that is, the second insulating layer on the positive electrode sheet is used to support the edge side or the electrical connection member of the negative electrode sheet, so as to reduce the extrusion on the end face of the negative electrode sheet.

[0026] In a second aspect, an embodiment of the present application further provides a battery, including the battery cell described above.

[0027] In a third aspect, an embodiment of the present application further provides an electrical device, including the battery described above.

[0028] It can be understood that for the beneficial effects of the above second aspect and third aspect, reference may be made to the relevant descriptions in the above first aspect, which will not be elaborated herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0030] Figure 1 It is a schematic structural diagram of the electrical device provided by an embodiment of the present utility model;

[0031] Figure 2 It is an exploded view of the battery provided by an embodiment of the present utility model;

[0032] Figure 3 It is a sectional view of the electrode sheet of the battery cell provided in Embodiment 1 of the present utility model;

[0033] Figure 4 For Figure 3 the enlarged view at A in;

[0034] Figure 5 It is a sectional view of the electrode sheet of the battery cell provided in Embodiment 2 of the present utility model;

[0035] Figure 6 It is a sectional view of the electrode sheet of the battery cell provided in Embodiment 3 of the present utility model;

[0036] Figure 7 It is a sectional view of two electrode sheets of the battery cell stacked after being provided in Embodiment 4 of the present utility model;

[0037] Figure 8 It is a sectional view of two electrode sheets of the battery cell stacked after being provided in Embodiment 5 of the present utility model.

[0038] Among them, the reference numerals in the drawings:

[0039] 10000, electrical device;

[0040] 1000, battery; 2000, controller; 3000, motor;

[0041] 100, Battery cell; 200, Battery box; 201, First part; 202, Second part;

[0042] 10, Electrode; 11, Current collector; 12, Active material layer; 13, Electrical connection member; 11a, First edge side; 11b, Second edge side; 14, First insulating layer; 15, Second insulating layer; 111, Substrate; 112, Conductive layer; 131, Main body portion; 132, Branch portion;

[0043] X, Width direction of the electrode; Y, Thickness direction of the electrode. Detailed implementation manners

[0044] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present utility model, and should not be construed as a limitation to the present utility model.

[0045] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model.

[0046] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, "a plurality of" means two or more, unless otherwise specifically defined.

[0047] In the present utility model, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0048] The battery cells in a battery generally include a positive electrode plate, a negative electrode plate, a separator, and a housing, etc. The positive electrode plate, the negative electrode plate, and the separator are assembled into an electrode assembly by means of winding or laminating, etc. The electrode assembly is placed in the housing and electrolyte is injected to form a battery cell.

[0049] During the production process of battery electrode plates, the positive electrode plate and the negative electrode plate will have powder falling off the active material coating during the winding or lamination process, which affects the performance of the battery cell; and, the positive electrode plate and the negative electrode plate need to be die-cut. The die-cutting of battery electrode plates refers to the processing process of cutting or slicing the battery electrode plates from the raw materials into the required size and shape. For example, tabs are cut out, etc. Die-cutting is one of the key steps in the manufacturing process of battery cells. Die-cutting operations are usually carried out using a die-cutting machine or a cutting tool. By placing the current collector in the appropriate position and then applying appropriate force or pressure, the current collector is cut into the required shape and size, and the quality and accuracy of the cutting directly affect the performance and stability of the battery cell.

[0050] In the related art, powder falls off the active material coating, and when the electrode plate is die-cut, burrs are easily generated at the cutting edge. The burrs are likely to pierce the separator, causing the positive electrode plate and the negative electrode plate to conduct electricity, and neither can ensure the insulation of the positive electrode plate and the negative electrode plate, easily leading to the risk of short circuit.

[0051] In view of this, the present application provides a battery cell, in which a first insulating layer and a second insulating layer are respectively arranged on the opposite sides of the active material layer of the electrode plate. The first insulating layer is used to cover and protect the transition region between the active material layer of the current electrode plate and the electrical connection member, reducing the influence of the particles formed during the winding process of the electrode plate on the transition region. At the same time, the second insulating layer at the second edge side of the current collector of the current electrode plate can also support the active material layer or the electrical connection member of the adjacent electrode plate, and has a probability of reducing the phenomenon of internal short circuit of the battery cell caused by the burrs at the edge of the electrode plate caused by slitting or die-cutting.

[0052] In the present application, the battery cell includes, but is not limited to, 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. The battery cell can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc. The battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells, and soft-pack battery cells.

[0053] The embodiments of the present application provide a battery cell 100 that can be used as a power source and can be applied to power-consuming devices 10,000 such as vehicles, mobile phones, portable devices, laptops, ships, spacecraft, and power tools. Among them, the vehicle can be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, etc.; the spacecraft includes airplanes, rockets, space shuttles, and spaceships, etc.; the electric toys include stationary or mobile electric toys, for example, game consoles, electric vehicle toys, electric ship toys, electric airplane toys, etc.; the power tools include metal cutting power tools, grinding power tools, assembly power tools, and iron-using power tools, for example, electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact electric drills, concrete vibrators, and electric planers, etc.

[0054] The battery cell 100 described in the embodiments of the present application is not limited to being applicable to the power-consuming devices 10,000 described above, but can also be applicable to all devices using the battery cell 100. However, for the sake of simplicity of description, the following embodiments will be described by taking an electric vehicle as an example.

[0055] For example, please refer to Figure 1 , the figure is a schematic structural diagram of a vehicle according to an embodiment of the present application. The vehicle can be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, etc. A battery 1000, a controller 2000, and a motor 3000 can be arranged inside the vehicle. The controller 2000 is used to control the power supply of the battery 1000 to the motor 3000. For example, the battery 1000 can be arranged at the bottom, the front end, or the rear end of the vehicle. The battery 1000 can be used for the power supply of the vehicle. For example, the battery 1000 can be used as the operating power source of the vehicle and be used for the circuit system of the vehicle, for example, for the working power requirements during the start, navigation, and operation of the vehicle. In another embodiment of the present application, the battery 1000 can not only be used as the operating power source of the vehicle, but also be used as the driving power source of the vehicle to replace or partially replace fuel or natural gas to provide driving power for the vehicle.

[0056] The battery 1000 mentioned in the embodiments of the present application refers to a single physical module that includes one or more battery cells 100 to provide higher voltage and capacity. Please refer to Figure 2, the battery 1000 may include a plurality of battery cells 100. The number of battery cells 100 and the connection conditions between the battery cells 100 may be set according to requirements to meet different power demands. Specifically, the plurality of battery cells 100 may be connected in series, in parallel, or in a series-parallel combination. A series-parallel combination refers to a mixture of series and parallel connections, so that the battery 1000 has a larger capacity or power. Optionally, the plurality of battery cells 100 may first be connected in series, in parallel, or in a series-parallel combination to form a battery 1000 module, and then a plurality of battery 1000 modules may be connected in series, in parallel, or in a series-parallel combination to form the battery 1000. That is to say, the plurality of battery cells 100 may directly form the battery 1000, or may first form a battery module, and then the battery modules form the battery 1000.

[0057] The battery 1000 further includes a battery case 200, and the interior of the battery case 200 has an accommodation space, and a plurality of battery cells 100 are accommodated in the accommodation space. As Figure 2 shown, the battery case 200 may include two parts, which are respectively referred to as a first part 201 and a second part 202 here. Please refer to the figure and the figure, and the figure shows a first part 201 of a battery case 200. The first part 201 and the second part 202 may be connected by means of buckling, bonding, etc. to form an accommodation space. After the plurality of battery cells 100 are connected in parallel, in series, or in a series-parallel combination with each other, they are placed in the box formed after the connection of the first part 201 and the second part 202. Among them, the shapes of the first part 201 and the second part 202 may be determined according to the shape formed by the combination of the plurality of battery cells 100.

[0058] Among them, the battery case 200 is used to protect at least one battery cell 100, thereby reducing the influence of liquid or other foreign objects outside the battery 1000 on the charging or discharging of at least one battery cell 100. Among them, the battery cell 100 may be in a cylindrical shape, a flat shape, a cuboid shape, or other shapes, etc., and the embodiments of the present application do not make any limitations in this regard. The packaging methods of the battery cell 100 include but are not limited to cylindrical battery cells 100, square battery cells 100, and soft-pack battery cells 100, etc., and the embodiments of the present application do not make specific limitations in this regard either.

[0059] In addition, the battery 1000 may further include other structures, which will not be elaborated one by one here. For example, the battery 1000 may further include a busbar component. The busbar component is used to realize the electrical connection between the plurality of battery cells 100, for example, to realize the parallel, series, or series-parallel connection between the plurality of battery cells 100. Specifically, the busbar component may realize the electrical connection between the battery cells 100 by connecting the electrode terminals of the battery cells 100. Further, the busbar component may be fixedly connected to the electrode terminals of the battery cells 100 by welding. Optionally, the busbar component may include a conductive mechanism, and the electric energy generated by the plurality of battery cells 100 may further pass through the conductive mechanism and lead out through the battery case 200.

[0060] Each battery cell 100 may be a lithium-ion battery cell 100, a lithium-sulfur battery cell 100, a sodium-ion battery cell 100 or a magnesium-ion battery cell 100, but is not limited thereto. The battery cell 100 may be cylindrical, flat, rectangular or in other shapes.

[0061] The battery cell 100 refers to the smallest unit constituting the battery 1000. Each battery cell 100 may be a secondary battery or a primary battery; it may also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto. The battery cell 100 may be cylindrical, flat, rectangular or in other shapes.

[0062] The positive electrode and negative plate in the battery cell 100 are the two poles of the battery 1000, and they play a vital role inside the battery. Among them, the positive electrode is usually composed of one or more positive active materials, such as oxides or phosphates. The function of the positive electrode is to accept electrons and release positive ions when the battery is discharged. The positive ions pass through the electrolyte, so that the battery cell 100 generates current. When charging, the positive electrode absorbs electrons and stores positive ions. Among them, the negative electrode is usually composed of one or more negative active materials, such as carbon or lithium. The function of the negative electrode is to release electrons and absorb positive ions when the battery cell 100 is discharged. When charging, the negative electrode absorbs positive ions and releases electrons. The positive electrode and negative plate play complementary roles in the battery cell 100. Through chemical reactions during the charging and discharging process, the battery cell 100 can store and release energy. This chemical reaction is the basis for the battery cell 100 to work and the principle that the battery can provide electrical energy.

[0063] Please refer to Figure 3 , Figure 4 and Figure 7 The battery cell 100 provided in the embodiment of the present application includes two electrode sheets 10 stacked in phase, where the two electrode sheets 10 refer to a positive electrode sheet and a negative electrode sheet, respectively. Usually, during the manufacturing process of the battery cell 100, the incoming positive electrode sheet and the negative electrode sheet are rolled materials, which are formed by unwinding and then pressing together. Therefore, there should be a separator between the two, and in terms of structure, the positive electrode sheet and the negative electrode sheet are stacked in phase.

[0064] The two pole pieces 10 each include a current collector 11 , an active material layer 12 coated on the current collector 11 , and an electrical connector 13 . The current collector 11 has a first edge side 11 a and a second edge side 11 b oppositely disposed. The electrical connector 13 is connected to the first edge side 11 a .

[0065] Here, the current collector 11 mainly serves as a conductor and carrier for the active material layer 12 in the battery cell 100, aggregating and outputting the current generated by the active material or inputting the electrode current to the active material to facilitate the conversion between chemical energy and electrical energy. The main function of the current collector 11 is to collect the current generated by the active material in the battery cell 100 to form a larger current for external output.

[0066] Generally, the current collector 11 adopts a sheet structure and is prepared from metal foils, such as copper foils, aluminum foils, etc. For example, the positive electrode plate of a lithium battery can use an aluminum foil, and the negative electrode plate can use a copper foil. Copper foils and aluminum foils themselves have a certain degree of flexibility, which can meet the winding process requirements for manufacturing the battery core. In addition, the thickness of copper foils and aluminum foils is thin, which can improve the energy density of lithium-ion batteries.

[0067] The active material layer 12 is a layer of material located on the surface of the current collector 11. The active material layer 12 participates in the electrochemical reaction of the battery cell 100 and adsorbs and releases lithium ions during the charge and discharge process. The presence of the active material layer 12 increases the effective surface area of the electrode plate 10, thereby improving its performance and energy density.

[0068] For example, in a lithium-ion battery cell, the material of the active material layer 12 of the positive electrode plate can be a lithium-ion compound. Correspondingly, the material of the active material layer 12 of the negative electrode plate can be a carbon material. The negative electrode plate absorbs lithium ions during charging and releases lithium ions after charging is completed to achieve the charge and discharge process of the battery cell 100.

[0069] For the positive electrode plate, its active material layer 12 usually includes lithium-ion compounds, such as cobalt oxide, nickel manganese cobalt oxide, etc. Specifically, the active material layer 12 can adopt lithium cobaltate coatings, lithium iron phosphate coatings, lithium manganate coatings, etc. The above compounds can absorb lithium ions during charging to form lithium compounds and release lithium ions after charging is completed.

[0070] For the negative electrode plate, its active material layer 12 usually includes carbon materials, such as graphite, etc. Carbon materials have good electrical conductivity and stability, can effectively adsorb and release lithium ions, and achieve the charge and discharge process of the battery.

[0071] The electrical connector 13 is an electrical structure used to output the current aggregated by the current collector 11 of the electrode plate 10 to the outside. Therefore, the electrical connector 13 is a structure similar to a busbar. At the same time, usually, the electrical connector 13 and the current collector 11 are electrically connected by welding.

[0072] At least one electrode tab 10 further includes a first insulating layer 14 and a second insulating layer 15. The first insulating layer 14 and the second insulating layer 15 are respectively disposed on opposite sides of the active material layer 12. Moreover, the side of the first insulating layer 14 away from the active material layer 12 extends towards the first edge side 11a, and the side of the second insulating layer 15 away from the active material layer 12 extends towards the second edge side 11b.

[0073] Understandably, the meaning of providing an insulating layer on at least one electrode tab 10 is that an insulating layer can be provided on one of the electrode tabs 10. For example, an insulating layer can be provided on the positive electrode tab or on the negative electrode tab; it is also possible to provide insulating layers on both electrode tabs 10. For example, insulating layers are provided on both the positive electrode tab and the negative electrode tab.

[0074] The materials of the first insulating layer 14 and the second insulating layer 15 can be the same or different. For example, the first insulating layer 14 can be made of a polymer film (such as polypropylene, polyethylene, polyimide, etc.), a ceramic material (such as alumina, etc.), a composite material, or a glass fiber material, etc. Specifically, for example, the first insulating layer 14 can be made of one or more of boehmite, calcium oxide, magnesium oxide, and calcium carbonate.

[0075] Similarly, the second insulating layer 15 also has the property and function of insulation. The second insulating layer 15 can also be made of a polymer film (such as polypropylene, polyethylene, polyimide, etc.), a ceramic material (such as alumina, etc.), a composite material, or a glass fiber material, etc. Specifically, for example, the second insulating layer 15 can be made of one or more of boehmite, calcium oxide, magnesium oxide, and calcium carbonate.

[0076] Since the active material layer 12 can be connected to the surface of the current collector 11 by means of coating, and the coating is carried out along the extending direction of the current collector 11. For example, if the incoming electrode tab 10 is in a rolled form, then the extending direction of the current collector 11 refers to the length direction in which the incoming electrode tab 10 is pulled and then wound. Moreover, the two edge sides of the current collector 11 are in terms of the width direction of the electrode tab 10, that is, the first edge side 11a and the second edge side 11b are the two side parts of the current collector 11 in the width direction of the electrode tab 10. Similarly, after the coating is completed on the current collector 11, the active material layer 12 also has side parts corresponding to the first edge side 11a and the second edge side 11b.

[0077] In summary, the first insulating layer 14 is located on one side of the active material layer 12 and extends towards the first edge side 11a of the current collector 11. That is, the first insulating layer 14 is coated on the area of the current collector 11 that does not cover the active material layer 12, which is also the transition area. Similarly, the second insulating layer 15 is located on one side of the active material layer 12 and extends towards the second edge side 11b of the current collector 11. That is, the second insulating layer 15 is coated on the area of the current collector 11 that does not cover the active material layer 12, which is also another transition area.

[0078] In the actual manufacturing process of the electrode sheet 10, first, the current collector 11 is prepared, then the active material layer 12 is coated on the surface of the current collector 11, and then the insulating layer is coated on the area of the current collector 11 where the active material layer 12 is not coated. Among them, in the width direction of the electrode sheet, the first insulating layer 14 is located on one side of the active material layer 12 and extends towards the first edge side 11a, and the second insulating layer 15 is located on the other side of the active material layer 12 and extends towards the second edge side 11b. After the above coating process is completed, the current collector 11 can be die-cut, and the die-cut position is the position where the insulating layer and the current collector 11 overlap. Of course, the manufacturing process can also be adjusted. The current collector 11 can be die-cut first, and then the insulating layer can be coated on the blank area of the current collector 11.

[0079] For the battery cell 100 provided in the present application, the first insulating layer 14 and the second insulating layer 15 are arranged on opposite sides of the active material layer 12 of at least one electrode sheet 10. The first insulating layer 14 is used to cover and protect the transition area between the active material layer 12 of the current electrode sheet 10 and the electrical connection member 13, reducing the influence of the transition area on the particles formed during the winding process of the electrode sheet 10. At the same time, the second insulating layer 15 located at the second edge side 11b of the current collector 11 of the current electrode sheet 10 can support the active material layer 12 or the electrical connection member 13 of the adjacent electrode sheet 10, so as to reduce the probability of internal short circuit of the battery cell 100 caused by the burrs at the edge of the electrode sheet 10 caused by slitting or die-cutting.

[0080] Please refer to Figures 3 to 6 In some embodiments, the first insulating layer 14 is connected to the active material layer 12; and / or, the second insulating layer 15 is connected to the active material layer 12.

[0081] It can be understood that the edge sides of the active material layer 12, that is, on the opposite sides of the active material layer 12 in the width direction of the electrode sheet 10, which are also the parts corresponding to the insulating layer, are the positions where the active material layer 12 is easily squeezed and cracked after the electrode sheet 10 is wound or laminated. The extrusion of the active material layer 12 to form particles is one of the factors leading to internal short circuit of the battery. Therefore, the insulating layer is connected to the edge side of the active material layer 12 to protect its edge side.

[0082] Here, according to the actual usage requirements, the connection form between the insulating layer and the active material can be: the edge side of the insulating layer is in contact with the edge side of the active material layer 12, and there is no mutual interference between the two in the width direction of the electrode sheet 10, and there is an obvious boundary between the edge side of the insulating layer and the edge side of the active material layer 12, or there is mutual interference, but it is within the process error range; or, the edge side of the insulating layer covers the edge side of the active material layer 12, then, looking from the thickness direction of the electrode sheet 10, there is a partial overlap in space between the two.

[0083] During actual use, it can be selected that the first insulating layer 14 is connected to the active material layer 12, and the second insulating layer 15 is not connected to the active material layer 12; or, it can be selected that the second insulating layer 15 is connected to the active material layer 12, and the first insulating layer 14 is not connected to the active material layer 12; or, both the first insulating layer 14 and the second insulating layer 15 are connected to the active material layer 12.

[0084] Exemplarily, as Figure 3 shown, the edge side of the first insulating layer 14 is in contact with one edge side of the active material layer 12, and there is an obvious boundary at the connection; the edge side of the second insulating layer 15 is in contact with the other edge side of the active material layer 12, and there is an obvious boundary at the connection. Thus, in the width direction of the electrode sheet 10, the relative two sides of the active material layer 12 are protected by the two insulating layers to reduce the probability of the edge of the active material layer 12 cracking during the winding process of the electrode sheet 10.

[0085] Thus, by using the first insulating layer 14 and / or the second insulating layer 15 to fix and wrap the side part of the active material layer 12, the probability of the active material layer 12 cracking or falling off during winding or laminating can be effectively reduced, and at the same time, the connection stability of the active material layer 12 on the current collector 11 can also be improved.

[0086] Please refer to Figure 5 , in some embodiments, in the width direction of the electrode sheet 10, the range of the width D1 of the first insulating layer 14 satisfies: 0.1 mm ≤ D1 ≤ 500 mm; and / or, the range of the width D2 of the second insulating layer 15 satisfies: 0.1 mm ≤ D2 ≤ 500 mm.

[0087] It can be understood that the width of the first insulating layer 14 is the width coated on the current collector 11 in the width direction of the electrode sheet 10. Here, the width D1 of the first insulating layer 14 can be 0.1 mm, 0.5 mm, 1 mm, 5 mm, 10 mm, 20 mm, 50 mm, 75 mm, 100 mm, 150 mm, 200 mm, 250 mm, 300 mm, 350 mm, 400 mm, 450 mm, 500 mm.

[0088] Similarly, the width of the second insulating layer 15 is the width coated on the current collector 11 in the width direction of the electrode sheet 10. Here, the width D1 of the second insulating layer 15 can be 0.1 mm, 0.5 mm, 1 mm, 5 mm, 10 mm, 20 mm, 50 mm, 75 mm, 100 mm, 150 mm, 200 mm, 250 mm, 300 mm, 350 mm, 400 mm, 450 mm, 500 mm.

[0089] In summary, according to the different battery models, the width of the insulating layer is adjusted to achieve the purpose of adaptation.

[0090] Please refer to Figure 5 , in some embodiments, the thickness of the first insulating layer 14 is greater than or equal to the thickness of the active material layer 12; and / or, the thickness of the second insulating layer 15 is greater than or equal to the thickness of the active material layer 12.

[0091] It can be understood that the thicknesses of the insulating layer and the active material layer 12 are both defined in the thickness direction of the electrode sheet 10, that is, in this direction, the heights of the insulating layer and the active material layer 12 on the current collector 11. Here, as shown in the figure, the thickness of the first insulating layer 14 can be defined as M, the thickness of the second insulating layer 15 can be defined as N, and the thickness of the active material layer 12 can be defined as O.

[0092] Optionally, during actual use, the thickness of the first insulating layer 14 is greater than or equal to the thickness of the active material layer 12, without limiting the thickness of the second insulating layer 15; or, the thickness of the second insulating layer 15 is greater than or equal to the thickness of the active material layer 12, without limiting the thickness of the first insulating layer 14; or, the thickness of the first insulating layer 14 is defined as greater than or equal to the thickness of the active material layer 12, and the thickness of the second insulating layer 15 is defined as greater than or equal to the thickness of the active material layer 12.

[0093] In this way, the first insulating layer 14 or the second insulating layer 15 of the current electrode sheet 10 can be used to support the first edge side 11a or the second edge side 11b of the adjacent electrode sheet 10, so as to reduce the probability of cracking or short circuit caused by extrusion deformation of the end face of the electrode sheet 10. At the same time, increasing the thickness of the insulating layer can also wrap the burrs formed during die-cutting of the current collector 11, so as to reduce the risk of burr exposure.

[0094] Please refer to Figure 6 , in some embodiments, in the thickness direction of the electrode sheet 10, the projection of the edge side of the first insulating layer 14 coincides with the projection of the edge side of the active material layer 12; and / or, the projection of the edge side of the second insulating layer 15 coincides with the projection of the edge side of the active material layer 12.

[0095] Understandably, when the edge side of the insulating layer is connected to the edge side of the active material layer 12, the connection positions of the two can coincide. That is, in the thickness direction of the electrode 10, there is an overlapping positional relationship between the edge side of the insulating layer and the edge side of the active material layer 12. Of course, it is based on the edge side of the insulating layer covering the edge side of the active material layer 12.

[0096] During actual use, it can be selected that the edge side of the first insulating layer 14 covers the edge side of the active material layer 12, and the edge side of the second insulating layer 15 is in contact with or spaced from the edge side of the active material layer 12; or, it can be selected that the edge side of the second insulating layer 15 covers the edge side of the active material layer 12, and the edge side of the first insulating layer 14 is in contact with or spaced from the edge side of the active material layer 12; or, the edge sides of the first insulating layer 14 and the second insulating layer 15 respectively cover the two edge sides of the active material layer 12.

[0097] In this way, the first insulating layer 14 and / or the second insulating layer 15 overlap with the active material layer 12 in the coating position, which can further improve the bonding stability at the connection between the insulating layer and the active material layer 12, and effectively reduce the probability of the active material layer 12 cracking or falling off during the winding or stacking process.

[0098] Please refer to Figure 5 , in some embodiments, the edge side of the first insulating layer 14 is spaced from the edge side of the active material layer 12; and / or, the edge side of the second insulating layer 15 is spaced from the edge side of the active material layer 12.

[0099] Understandably, there is a certain gap or slit between the edge side of the insulating layer and the edge side of the active material layer 12. That is, the two edge sides do not come into direct contact. Specifically, a gap is formed between the edge side of the first insulating layer 14 and the edge side of the active material layer 12; or, a gap is formed between the edge side of the second insulating layer 15 and the edge side of the active material layer 12; or, gaps are formed between the edge sides of the two insulating layers and the two opposite edge sides of the active material layer 12 respectively.

[0100] Due to cost considerations, there are differences in the selection of insulating layers. Especially for cost control, some insulating layers with relatively low thermal stability are selected. Then, during the use of the battery, the internal temperature rises to the critical value of the melting point of the insulating layer, making the thermal stability of the insulating layer easily damaged. The insulating layer is prone to melting and penetration with the active material layer 12, resulting in an unclear boundary between the active material layer 12 and the insulating layer, leading to a decline in battery performance. Because the main function of the insulating layer is to prevent the active material layer 12 from directly contacting the electrolyte, thereby reducing the risk of short circuit. If the boundary is blurred, it may increase the possibility of short circuit, resulting in unstable battery performance. In addition, an unclear boundary may cause unnecessary chemical reactions during the charge and discharge process of the battery, thereby increasing the risk of battery heating or even catching fire. Moreover, an unclear boundary between the active material layer 12 and the insulating layer may cause excessive diffusion of the active material in the active material layer 12 during the charge and discharge process of the battery, accelerating battery aging and thus shortening the service life of the battery, etc.

[0101] In this way, a gap is formed between the first insulating layer 14 and / or the second insulating layer 15 and the edge of the active material layer 12 to reduce the risk of melting and penetration between the insulating layer and the active material layer 12, which is beneficial to improving the reliability during the use of the battery.

[0102] Please refer to Figure 3 and Figure 4 , in some embodiments, the side of the first insulating layer 14 away from the active material layer 12 extends towards the electrical connection member 13 and is spaced apart from the edge side of the electrical connection member 13.

[0103] It can be understood that in the width direction of the electrode sheet 10, the two edge sides of the first insulating layer 14 face the active material layer 12 and the electrical connection member 13 respectively, that is, the first insulating layer 14 is located between the active material layer 12 and the electrical connection member 13. Here, it is defined that a gap or slit is formed between the edge side of the first insulating layer 14 facing the electrical connection member 13 and the edge side of the electrical connection member 13.

[0104] In this way, a slit is formed between the edge side of the first insulating layer 14 and the edge side of the electrical connection member 13. Similarly, when the electrode sheet 10 is wound or laminated, the probability of the edge of the first insulating layer 14 falling off, delaminating and cracking due to being squeezed by the electrical connection member 13 can be reduced.

[0105] Please refer to Figure 4 , in one embodiment, the distance between the side of the first insulating layer 14 away from the active material layer 12 and the edge side of the electrical connection member 13 is D3, and the range of D3 satisfies: 0.1 mm ≤ D3 ≤ 50 mm.

[0106] Understandably, D3 can be 0.1mm, 0.5mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm.

[0107] In this way, according to different models of the battery, the distance between the edge side of the first insulating layer 14 and the edge side of the electrical connection member 13 can be adjusted to protect the first insulating layer 14 and reduce the risk of cracking and tape breakage due to extrusion.

[0108] Please refer to Figure 3 、 Figure 4 and Figure 6 In some embodiments, the current collector 11 includes a substrate 111 and conductive layers 112 formed on opposite end faces of the substrate 111. The active material layer 12, the first insulating layer 14, and the second insulating layer 15 are all coated on the conductive layer 112. The electrical connection member 13 includes a main body portion 131 and a branch portion 132 connected to the main body portion 131. The main body portion 131 is electrically connected to one of the conductive layers 112, and the branch portion 132 is electrically connected to the other conductive layer 112.

[0109] Understandably, the current collector 11 in this embodiment is a structurally composite current collector, which is composed of a three-layer structure, that is, a substrate 111 and two conductive layers 112. Among them, the material of the substrate 111 includes but is not limited to epoxy resin, polyamide, polyester resin, etc.; the material of the conductive layer 112 includes carbon fiber, metal particles, conductive carbon black, etc.

[0110] According to actual usage requirements, the active material layer 12, the first insulating layer 14, and the second insulating layer 15 can be coated on one or two of the conductive layers 112.

[0111] Since the conductive layers 112 of the current collector 11 are located on opposite end sides, the structure of the electrical connection member 13 also needs to be adjusted accordingly. Specifically, the electrical connection member 13 includes a main body portion 131 and a branch portion 132 connected to the main body portion 131. The main body portion 131 and the branch portion 132 form a structure similar to a "Y" shape, and the open shape of this structure is used to achieve electrical connection with the two conductive layers 112. Therefore, the main body portion 131 is welded to one of the conductive layers 112, and the branch portion 132 is welded to the other conductive layer 112.

[0112] Due to its structure, the composite current collector can simultaneously meet the design requirements of high strength and lightweight, and has a longer service life.

[0113] Please refer to Figure 7 and Figure 8, in some embodiments, the electrode sheet 10 includes a positive electrode sheet and a negative electrode sheet;

[0114] In the thickness direction of the electrode sheet 10, the projection of the first edge side 11a of the negative electrode sheet falls within the projection of the second insulating layer 15 of the positive electrode sheet; or,

[0115] the projection of the electrical connection member 13 of the negative electrode sheet falls within the projection of the second insulating layer 15 of the positive electrode sheet;

[0116] the projection of the second edge side 11b of the negative electrode sheet falls within the projection of the first insulating layer 14 of the positive electrode sheet.

[0117] It can be understood that the first edge side 11a of the negative electrode sheet refers to the first edge side 11a of the current collector 11 of the negative electrode sheet, and when the electrical connection member 13 is provided on the negative electrode sheet, it can be selectively provided on the first edge side 11a of the negative electrode sheet. Similarly, the second edge side 11b of the negative electrode sheet refers to the second edge side 11b of the current collector 11 of the negative electrode sheet.

[0118] During the winding process of the positive electrode sheet and the negative electrode sheet, the width of the active material layer 12 on the negative electrode sheet should be greater than the width of the active material layer 12 on the positive electrode sheet, that is, in the thickness direction of the electrode sheet 10, the projection of the active material layer 12 on the positive electrode sheet should fall within the projection range of the active material layer 12 on the negative electrode sheet. Therefore, on the basis of not setting an insulating layer, the burrs formed after the positive electrode sheet is die-cut may pierce through the separator to the negative electrode sheet, resulting in a battery short circuit phenomenon.

[0119] To solve the above problems, a first insulating layer 14 and a second insulating layer 15 are provided on the positive electrode sheet, and the first edge side 11a and the second edge side 11b of the negative electrode sheet are respectively corresponding to the second insulating layer 15 and the first insulating layer 14. Specifically, in the thickness direction of the electrode sheet 10, the projection of the first edge side 11a of the negative electrode sheet falls within the projection of the second insulating layer 15 of the positive electrode sheet; the projection of the second edge side 11b of the negative electrode sheet falls within the projection of the first insulating layer 14 of the positive electrode sheet. In this way, the die-cutting part of the positive electrode sheet is coated by each insulating layer, reducing the probability of burr exposure. At the same time, the insulating layer can also support the edge side of the negative electrode sheet, effectively reducing the risk of cracking or short circuit caused by the end face of the negative electrode sheet being squeezed and deformed.

[0120] Or, when the electrical connection member 13 is provided on the edge side of the negative electrode sheet, the electrical connection member 13 on the negative electrode sheet can also be supported by the insulating layer on the positive electrode sheet, effectively reducing the probability of the welding area between the electrical connection member 13 and the current collector 11 of the negative electrode sheet being de-welded, delaminated or cracked due to extrusion.

[0121] Please refer to Figures 3 to 7, in a specific embodiment, the battery cell 100 includes two electrode plates 10 stacked on top of each other.

[0122] Each electrode plate 10 includes a current collector 11, an active material layer 12 coated on the current collector 11, and an electrical connection member 13. The current collector 11 has a first edge side 11a and a second edge side 11b disposed opposite to each other, and the electrical connection member 13 is connected to the first edge side 11a.

[0123] The first insulating layer 14 is connected to the active material layer 12, and the second insulating layer 15 is connected to the active material layer 12. Moreover, in the thickness direction of the electrode plate 10, the projection of the edge side of the first insulating layer 14 coincides with the projection of the edge side of the active material layer 12; the projection of the edge side of the second insulating layer 15 coincides with the projection of the edge side of the active material layer 12.

[0124] The range of the width D1 of the first insulating layer 14 satisfies: 0.1 mm ≤ D1 ≤ 500 mm; the range of the width D2 of the second insulating layer 15 satisfies: 0.1 mm ≤ D2 ≤ 500 mm.

[0125] The side of the first insulating layer 14 away from the active material layer 12 extends toward the electrical connection member 13 and is spaced apart from the edge side of the electrical connection member 13. The distance between the side of the first insulating layer 14 away from the active material layer 12 and the edge side of the electrical connection member 13 is D3, and the range of D3 satisfies: 0.1 mm ≤ D3 ≤ 50 mm.

[0126] The thickness of the first insulating layer 14 is equal to the thickness of the active material layer 12; the thickness of the second insulating layer 15 is greater than the thickness of the active material layer 12.

[0127] The current collector 11 includes a substrate 111 and conductive layers 112 formed on opposite end faces of the substrate 111. The active material layer 12, the first insulating layer 14, and the second insulating layer 15 are all coated on the conductive layer 112. The electrical connection member 13 includes a main body portion 131 and a branch portion 132 connected to the main body portion 131. The main body portion 131 is electrically connected to one of the conductive layers 112, and the branch portion 132 is electrically connected to the other conductive layer 112.

[0128] The electrode plate 10 includes a positive electrode plate and a negative electrode plate; in the thickness direction of the electrode plate 10, the projection of the first edge side 11a of the negative electrode plate falls within the projection of the second insulating layer 15 of the positive electrode plate; the projection of the second edge side 11b of the negative electrode plate falls within the projection of the first insulating layer 14 of the positive electrode plate.

[0129] The embodiment of the present application also provides a battery, including the battery cell 100 described above.

[0130] The embodiment of the present application also provides an electrical device, including the battery described above.

[0131] Understandably, for the beneficial effects of the above second aspect and third aspect, reference may be made to the relevant descriptions in the above first aspect, which will not be elaborated here.

[0132] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A battery cell, characterized in that: It includes two pole pieces arranged in a stacked manner; Each of the pole pieces comprises a current collector, an active material layer coated on the current collector, and an electrical connector, the current collector has a first edge side and a second edge side arranged opposite to each other, and the electrical connector is connected to the first edge side; At least one of the pole pieces also includes a first insulating layer and a second insulating layer, wherein the first insulating layer and the second insulating layer are respectively arranged on opposite sides of the active material layer, and a side of the first insulating layer away from the active material layer extends toward the first edge side, and a side of the second insulating layer away from the active material layer extends toward the second edge side.

2. The battery cell according to claim 1, characterized in that: The first insulating layer is connected to the active material layer; and / or the second insulating layer is connected to the active material layer.

3. The battery cell according to claim 2, characterized in that: The thickness of the first insulating layer is greater than or equal to the thickness of the active material layer; and / or the thickness of the second insulating layer is greater than or equal to the thickness of the active material layer.

4. The battery cell according to claim 2, characterized in that: In the thickness direction of the electrode sheet, the projection of the edge side of the first insulating layer coincides with the projection of the edge side of the active material layer; and / or the projection of the edge side of the second insulating layer coincides with the projection of the edge side of the active material layer.

5. The battery cell according to claim 1, characterized in that: The first insulating layer is disposed at a distance from an edge side of the active material layer; and / or the edge side of the second insulating layer is disposed at a distance from an edge side of the active material layer.

6. The battery cell according to any one of claims 1 to 5, characterized in that: The first insulating layer extends from a side of the active material layer toward the electrical connection component and is spaced apart from an edge of the electrical connection component.

7. The battery cell according to any one of claims 1 to 5, characterized in that: The current collector includes a substrate and a conductive layer formed on two opposite end surfaces of the substrate, the active material layer, the first insulating layer and the second insulating layer are all coated on the conductive layer, and the electrical connector includes a main body and a branch connected to the main body, the main body is electrically connected to one of the conductive layers, and the branch is electrically connected to the other conductive layer.

8. The battery cell according to any one of claims 1 to 5, characterized in that: The pole pieces include a positive pole piece and a negative pole piece, in the thickness direction of the pole pieces; The projection of the first edge of the negative electrode sheet falls within the projection of the second insulating layer of the positive electrode sheet; or, The projection of the electrical connector of the negative electrode sheet falls within the projection of the second insulating layer of the positive electrode sheet; The projection of the second edge side of the negative electrode sheet falls within the projection of the first insulating layer of the positive electrode sheet.

9. A battery, characterized in that: The invention comprises a battery cell as claimed in any one of claims 1 to 8.

10. An electrical equipment, characterized in that: Comprising the battery as claimed in claim 9.

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