Electrode assembly, battery cell, battery and electric device

Abstract

The utility model provides an electrode assembly, a battery monomer, a battery and an electric device, in the electrode assembly, a second pole piece and a first pole piece are laminated, and the second pole piece comprises a second current collector, a second active material layer and a second tab; the second current collector comprises a second coating area coated with a second active material layer and a second blank area not coated with the second active material layer, and the second tab is provided with a second connecting area connected with the second blank area; the separator is used for separating the first pole piece from the second pole piece; and in the lamination direction of the first pole piece and the second pole piece, at least part of the insulating layer is positioned between the first active material layer and the second blank area. The insulating layer is arranged between the second blank area and the first active material layer, so that the insulating layer capable of playing an insulating protection role is also arranged between the second blank area and the first pole piece, the second pole lug is not easy to penetrate into the first pole piece, and the possibility of short circuit between the first pole piece and the second pole piece is reduced; therefore, the electrode assembly has good reliability.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to an electrode assembly, a battery cell, a battery and an electrical device. Background Art

[0002] Batteries have the advantages of high specific energy and high power density. They are widely used in electronic devices and transportation vehicles, such as mobile phones, laptops, electric vehicles, electric airplanes, electric ships, electric tools, etc.

[0003] As the application scope of batteries continues to expand, people's requirements for battery reliability are becoming higher and higher. How to improve the reliability of batteries has attracted more and more attention from technicians in this field. Utility Model Content

[0004] In view of the above problems, the present application provides an electrode assembly, a battery cell, a battery and an electrical device, wherein the electrode assembly helps to improve the reliability of the battery.

[0005] In a first aspect, some embodiments of the present application provide an electrode assembly, comprising a first pole piece, a second pole piece, an isolating member and an insulating layer, the first pole piece comprising a first active material layer; the second pole piece is stacked with the first pole piece, the second pole piece comprising a second current collector, a second active material layer and a second pole lug, the second current collector comprising a second coated area coated with the second active material layer and a second blank area not coated with the second active material layer, the second pole lug having a second connecting area connected to the second blank area; the isolating member is used to isolate the first pole piece and the second pole piece; in the stacking direction of the first pole piece and the second pole piece, at least part of the insulating layer is located between the first active material layer and the second blank area and covers the second connecting area.

[0006] By arranging the insulating layer between the second blank area and the first active material layer, there is not only an isolation member between the second blank area and the first pole piece, but also an insulating layer that can play an insulating protection role, so that the second pole ear is not easy to pierce the first pole piece, reducing the possibility of short circuit between the first pole piece and the second pole piece, so that the electrode assembly has good reliability, which helps to improve the reliability of the battery.

[0007] According to the electrode assembly provided in some embodiments of the present application, the insulating layer is attached to the first active material layer, so that the insulating layer can reduce the escape of ions from the first active material layer.

[0008] According to the electrode assembly provided in some embodiments of the present application, in the stacking direction, the projection of the second blank area is located within the projection of the insulating layer, so that the insulating layer can cover the entire second blank area, so that the insulating layer has a better covering effect on the connection position between the second pole ear and the second blank area, further reducing the possibility of the second pole ear piercing the first pole piece.

[0009] According to the electrode assembly provided in some embodiments of the present application, the first pole piece, the second pole piece and the isolation member are wound along a winding direction; the second active material layer and the second blank area define a first recess, and the first recess forms an opening at at least one end along the first direction, and the first direction is perpendicular to the winding direction; the second pole ear also includes a second extension area connected to the second connecting area, the second connecting area is accommodated in the first recess, and the second extension area protrudes from the second blank area along the first direction, so as to facilitate the connection of the second pole ear with other components.

[0010] According to the electrode assembly provided in some embodiments of the present application, a second insulating layer is provided in the first recess, and the second insulating layer covers the connection between the second pole ear and the second blank area, which not only increases the connection strength between the second pole ear and the second blank area, but also can insulate and protect the connection between the second pole ear and the second blank area, further making it difficult for the second pole ear to pierce the first pole piece, reducing the possibility of short circuit between the first pole piece and the second pole piece, thereby improving the reliability of the electrode assembly.

[0011] In a second aspect, some embodiments of the present application provide a battery cell, which includes a housing and an electrode assembly provided by any of the above technical solutions, wherein the electrode assembly is accommodated in the housing.

[0012] According to the battery cell provided in some embodiments of the present application, the battery cell further includes an insulating sheet, which is located on one side of the second active material layer; the housing includes a first electrode lead-out piece, which is located on the side of the insulating sheet away from the active material layer, and the insulating sheet is provided with a first through hole, and the second pole ear passes through the first through hole and is connected to the first electrode lead-out piece. By passing the second pole ear connected to the second blank area through the first through hole of the insulating sheet, the inner wall of the first through hole can support the second pole ear, thereby reducing the flattening of the pole ear and reducing the space occupied by the pole ear of the current collector, which is conducive to improving the energy density of the battery cell.

[0013] According to the battery cell provided in some embodiments of the present application, the battery cell also includes a current collecting member connected to the first electrode lead-out member, the current collecting member is arranged between the insulating sheet and the first electrode lead-out member, and the second electrode tab is connected to the current collecting member through the first through hole, so that the second electrode tab and the first electrode lead-out member can be conveniently connected through the current collecting member.

[0014] According to the battery cells provided in some embodiments of the present application, the current collecting member is provided with a second through hole connected to the first through hole, and the second pole ear passes through the first through hole and the second through hole and is connected to the surface of the current collecting member facing away from the insulating sheet, so that the second pole ear can be connected to the surface of the current collecting member facing away from the insulating sheet.

[0015] According to the battery cells provided in some embodiments of the present application, the current collecting component includes a conduit and a transition portion connected to the conduit, the second through hole is opened in the conduit, the conduit is located between the insulating sheet and the first electrode lead-out member and is connected to the second electrode ear, and the transition portion is bent toward the first electrode lead-out member and connected to the first electrode lead-out member, so that the connection area between the transition portion and the first electrode lead-out member is larger, which is beneficial to improving the connection firmness between the transition portion and the first electrode lead-out member.

[0016] According to the battery cell provided in some embodiments of the present application, a plurality of second pole ears are provided, a plurality of first through holes are provided, the plurality of first through holes are arranged at intervals, and the plurality of second pole ears respectively pass through the plurality of first through holes to be connected to the first electrode lead-out member, so that the plurality of second pole ears respectively pass through the plurality of first through holes one by one to be connected to the first electrode lead-out member, which is beneficial to reduce the occurrence of the plurality of second pole ears being entangled or adhered together.

[0017] In a third aspect, some embodiments of the present application further provide a battery, which includes the battery cell provided by the above technical solution.

[0018] In a fourth aspect, some embodiments of the present application further provide an electrical device, which includes a battery provided by the above technical solution, and the battery is used to provide electrical energy.

[0019] The technical solution provided by the embodiments of the present disclosure brings at least the following beneficial effects:

[0020] Some embodiments of the present application provide an electrode assembly, the electrode assembly comprising a first pole piece, a second pole piece, a separator and an insulating layer, the first pole piece comprising a first active material layer; the second pole piece is stacked with the first pole piece, the second pole piece comprises a second current collector, a second active material layer and a second pole ear, the second current collector comprises a second coating area coated with a second active material layer and a second blank area not coated with the second active material layer, and the second pole ear has a second connection area connected to the second blank area; the separator is used to isolate the first pole piece and the second pole piece; in the stacking direction of the first pole piece and the second pole piece, at least part of the insulating layer is located between the first active material layer and the second blank area and covers the second connection area. By arranging the insulating layer between the second blank area and the first pole piece and covering the second connection area, there is not only a separator between the second blank area and the first pole piece, but also an insulating layer that can play an insulating protection role, so that the second pole ear is not easy to penetrate the first pole piece, reducing the possibility of short circuit between the first pole piece and the second pole piece, so that the electrode assembly has good reliability, thereby helping to improve the reliability of the battery.

[0021] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0023] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0024] Figure 2 An exploded view of a battery provided in some embodiments of the present application;

[0025] Figure 3 An exploded view of a battery module provided in some embodiments of the present application;

[0026] Figure 4 A cross-sectional view of a battery cell provided in some embodiments of the present application;

[0027] Figure 5 A cross-sectional view of a battery cell provided in some other embodiments of the present application;

[0028] Figure 6 A cross-sectional view of a second pole piece provided in some embodiments of the present application;

[0029] Figure 7 A top view of a first pole piece provided in some embodiments of the present application;

[0030] Figure 8 A schematic diagram of the structure of an electrode assembly provided in some embodiments of the present application;

[0031] Fig. 9 A top view of a second pole piece provided in some embodiments of the present application;

[0032] Fig.10 A cross-sectional view of a first pole piece provided in some embodiments of the present application;

[0033] Fig.11 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application;

[0034] Fig.12 A top view of an insulating sheet provided in some embodiments of the present application;

[0035] Fig.13 A top view of a current collecting component provided in some embodiments of the present application.

[0036] The reference numerals in the specific implementation manner are as follows:

[0037] 1. Vehicle; 2. Battery; 3. Controller; 4. Motor; 5. Box; 5a. First box portion; 5b. Second box portion; 5c. Accommodation space; 6. Battery module; 7. Battery cell; 71. Insulating sheet; 711. First through hole; 72. Current collecting member; 721. Converging portion; 7211. Second through hole; 722. Adapter; 20. Shell; 201. First electrode lead-out member; 202. Shell; 203. Cover; 30. Electrode assembly; 301. First pole piece; 3011. First current collector; 30111. First coating area; 30 112, first blank area; 3012, first active material layer; 3013, first pole ear; 30131, first connection area; 30132, first extension area; 302, second pole piece; 3021, second current collector; 30211, second coating area; 30212, second blank area; 3022, second active material layer; 3023, second pole ear; 30231, second connection area; 30232, second extension area; 3024, first recess; 303, isolation member; 304, insulating layer; 305, second insulating layer; X, first direction. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0039] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0040] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0041] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0042] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0043] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0044] In the embodiments of the present application, "parallel" includes not only the absolutely parallel situation, but also the roughly parallel situation conventionally recognized in engineering; at the same time, "perpendicular" also includes not only the absolutely perpendicular situation, but also the roughly perpendicular situation conventionally recognized in engineering. For example, if the angle between two directions is 85°-90°, the two directions can be considered perpendicular; if the angle between two directions is 0°-5°, the two directions can be considered parallel.

[0045] The term "plurality" used in the present application refers to two or more (including two).

[0046] At present, judging from the development of the market situation, the application of batteries is becoming more and more extensive. Batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields.

[0047] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0048] The battery cell may be a secondary battery cell, which refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0049] The battery cells may be lithium-ion battery cells, sodium-ion battery cells, sodium-lithium-ion battery cells, lithium metal battery cells, sodium metal battery cells, lithium-sulfur battery cells, magnesium-ion battery cells, nickel-hydrogen battery cells, nickel-cadmium battery cells, lead-acid battery cells, etc.

[0050] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and removed between the positive electrode and the negative electrode. The separator is set between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting, while allowing active ions to pass through.

[0051] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive electrode and the negative electrode. The present application has no specific restrictions on the type of electrolyte, which can be selected according to needs. The electrolyte can be liquid, gel or solid.

[0052] In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

[0053] In some embodiments, the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0054] In some embodiments, the solvent can be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent can also be selected from ether solvents. Ether solvents can include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether and crown ether.

[0055] The gel electrolyte includes a polymer-based electrolyte skeleton network combined with an ionic liquid-lithium salt.

[0056] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0057] As an example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, and the like.

[0058] As an example, the inorganic solid electrolyte can be an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphide, germanium argentum sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0059] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0060] In some embodiments, the electrode assembly is a wound structure. Optionally, the electrode assembly is a cylindrical wound structure.

[0061] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

[0062] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, a polygonal battery, such as a hexagonal battery.

[0063] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0064] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are accommodated in the case.

[0065] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0066] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0067] The first pole piece and the second pole piece in the electrode assembly are stacked and separated by a separator in the middle to prevent short circuit. In the related art, in order to lead out the electric energy of the pole piece, a pole ear is usually provided on the pole piece. Since the pole ear is usually connected to the pole piece by welding, there are spikes that pierce the separator at the connection position between the pole ear and the pole piece, which is not conducive to the stable operation of the electrode assembly and has an adverse effect on the reliability of the battery.

[0068] In order to improve the reliability of the battery, an embodiment of the present application provides an electrode assembly, in which the second current collector of the second pole piece includes a second coated area coated with a second active material layer and a second blank area not coated with the second active material layer, and the second pole ear has a second connecting area connected to the second blank area. By providing an insulating layer between the second blank area and the first active material layer, there is not only an isolation member between the second blank area and the first pole piece, but also an insulating layer that can play an insulating protection role, so that the second pole ear is not easy to pierce the first pole piece, reducing the possibility of short circuit between the first pole piece and the second pole piece, so that the electrode assembly has good reliability, thereby helping to improve the reliability of the battery.

[0069] The electrode assembly described in the embodiments of the present application is applicable to a battery cell, a battery, and an electrical device using the battery.

[0070] The electrical device may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The vehicle may be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, and the like; the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, and the like; the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like; the electric tool may include a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and an electric tool for railways, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, and the like. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0071] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device in an embodiment of the present application.

[0072] Figure 1 A schematic diagram of the structure of a vehicle provided for some embodiments of the present application.

[0073] like Figure 1 As shown, a battery 2 is disposed inside the vehicle 1, and the battery 2 may be disposed at the bottom, head, or tail of the vehicle 1. The battery 2 may be used to power the vehicle 1, for example, the battery 2 may be used as an operating power source for the vehicle 1.

[0074] The vehicle 1 may further include a controller 3 and a motor 4 , wherein the controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1 .

[0075] In some embodiments of the present application, the battery 2 can not only serve as an operating power source for the vehicle 1, but also serve as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0076] Figure 2 Schematic diagram of an explosion of a battery provided in some embodiments of the present application. Figure 2 As shown, the battery 2 includes a housing 5 and a battery cell (not shown), and the battery cell is accommodated in the housing 5. The battery cell may be the smallest unit constituting the battery.

[0077] The box 5 is used to accommodate the battery cells, and the box 5 can be of various structures. In some embodiments, the box 5 can include a first box portion 5a and a second box portion 5b, the first box portion 5a and the second box portion 5b cover each other, and the first box portion 5a and the second box portion 5b jointly define a storage space 5c for accommodating the battery cells. The second box portion 5b can be a hollow structure with one end open, the first box portion 5a is a plate-like structure, and the first box portion 5a covers the open side of the second box portion 5b to form a box 5 with a storage space 5c; the first box portion 5a and the second box portion 5b can also be hollow structures with one side open, and the open side of the first box portion 5a covers the open side of the second box portion 5b to form a box 5 with a storage space 5c. Of course, the first box portion 5a and the second box portion 5b can be of various shapes, such as a cylinder, a cuboid, etc.

[0078] In order to improve the sealing performance after the first box body part 5a and the second box body part 5b are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body part 5a and the second box body part 5b.

[0079] Assuming that the first box body portion 5a covers the top of the second box body portion 5b, the first box body portion 5a can also be called an upper box cover, and the second box body portion 5b can also be called a lower box.

[0080] In the battery 2, there can be one or more battery cells. If there are multiple battery cells, the multiple battery cells can be connected in series, in parallel, or in mixed connection. Mixed connection means that the multiple battery cells are both connected in series and in parallel. The multiple battery cells can be directly connected in series, in parallel, or in mixed connection, and then the whole formed by the multiple battery cells is accommodated in the box 5; of course, multiple battery cells can also be connected in series, in parallel, or in mixed connection to form a battery module 6, and the multiple battery modules 6 are then connected in series, in parallel, or in mixed connection to form a whole, and accommodated in the box 5.

[0081] Figure 3 for Figure 2 An exploded schematic diagram of the battery module is shown.

[0082] like Figure 3 As shown, in some embodiments, there are multiple battery cells 7, and the multiple battery cells 7 are first connected in series, in parallel, or in mixed connection to form a battery module 6. The multiple battery modules 6 are then connected in series, in parallel, or in mixed connection to form a whole, and are accommodated in a box.

[0083] The multiple battery cells 7 in the battery module 6 can be electrically connected through a busbar component to achieve parallel connection, series connection or mixed connection of the multiple battery cells 7 in the battery module 6 .

[0084] The battery cell 7 may be a cylindrical battery cell, a square battery cell, or a battery cell of other shapes.

[0085] like Figure 4 As shown, in some embodiments, the battery cell 7 includes a housing 20 and an electrode assembly 30. The electrode assembly 30 is accommodated in the housing 20. The electrode assembly 30 is a cylindrical winding structure.

[0086] The housing 20 may be in various shapes and sizes, such as a rectangular parallelepiped, a hexagonal prism, etc. Specifically, the shape of the housing 20 may be determined according to the specific shape and size of the electrode assembly 30. The housing 20 may be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and the present embodiment of the application does not impose any special restrictions on this.

[0087] The electrode assembly 30 is a component where electrochemical reactions occur in the battery cell 7. One or more electrode assemblies 30 may be contained in the housing 20.

[0088] Some embodiments of the present application provide an electrode assembly 30, such as Figure 5 As shown, the electrode assembly 30 includes a first electrode sheet 301, a second electrode sheet 302, an isolating member 303 and an insulating layer 304, the first electrode sheet 301 includes a first active material layer 3012; the second electrode sheet 302 is stacked with the first electrode sheet 301, the second electrode sheet 302 includes a second current collector 3021, a second active material layer 3022 and a second electrode ear 3023, the second current collector 3021 includes a second coated area 30211 coated with the second active material layer 3022 and a second blank area 30212 not coated with the second active material layer 3022, the second electrode ear 3023 has a second connection area connected to the second blank area 30212; the isolating member 303 is used to isolate the first electrode sheet 301 and the second electrode sheet 302; in the stacking direction of the first electrode sheet 301 and the second electrode sheet 302, at least part of the insulating layer 304 is located between the first electrode sheet 301 and the second blank area 30212 and covers the second connection area.

[0089] The first active material layer 3012 and the second active material layer 3022 may be active material layers having different electrode characteristics. Both may be formed by coating two active materials having different electrode characteristics on the first current collector 3011 and the second current collector 3021 , respectively.

[0090] As an example, the first active material layer 3012 includes a positive electrode active material. The positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for the battery 2 may also be used. These positive electrode active materials may be used alone or in combination of two or more.

[0091] Examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM 333 )、LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 )、LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 )、LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 )、LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2) and its modified compounds, etc.

[0092] As an example, the second active material layer 3022 includes a negative electrode active material. The negative electrode active material may be a negative electrode active material for a battery cell 7 that is well known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for battery 2 may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0093] The second current collector 3021 and the first current collector 3011 may be structures having electrical conductivity, which may be formed by providing a conductive material on an insulating substrate. For example, the conductive material on the second current collector 3021 and the first current collector 3011 may include a metal material, and the metal material includes aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver or silver alloy, etc.

[0094] Exemplarily, the first current collector 3011 and the second current collector 3021 may be formed by depositing different metal materials on the surfaces of two insulating substrates. Exemplarily, the conductive material on the first current collector 3011 may include a positive electrode metal, and the conductive material on the second current collector 3021 may include a negative electrode metal. The positive electrode metal included in the conductive material on the first current collector 3011 may be aluminum, and the negative electrode metal included in the conductive material on the second current collector 3021 may be copper. In some embodiments, the first current collector 3011 or the second current collector 3021 may be formed by spraying aluminum or copper on the surface of the insulating substrate through a spraying process.

[0095] like Figure 6 As shown, the second coating area 30211 and the second blank area 30212 are different areas on the second current collector 3021. The second coating area 30211 may be an area on the surface of the second current collector 3021 coated with the second active material layer 3022; the second blank area 30212 may be an area on the surface of the second current collector 3021 not coated with the second active material layer 3022. Since the surface of this area is not coated with the second active material layer 3022, the second current collector 3021 can be exposed so that the second pole piece 302 is electrically connected to other components.

[0096] For example, the second coating area 30211 may be an area on the surfaces of both sides of the second current collector 3021 coated with the second active material layer 3022, that is, the surfaces of both sides of the second current collector 3021 are provided with the second coating area 30211. The second blank area 30212 may be an area on one of the surfaces on both sides of the second current collector 3021 that is not coated with the second active material layer 3022, and the second pole piece 302 may be connected to any one of the surfaces on both sides of the second current collector 3021.

[0097] The second pole tab 3023 is a conductive member made of a conductive material. The second connection region 30231 may be a partial structure in the second pole tab 3023, which is used to connect with the second current collector 3021. By connecting the second connection region 30231 to the second blank region 30212, the second pole tab 3023 is directly in contact with the second current collector 3021 to conduct the electrical energy of the second pole tab 3023.

[0098] Exemplarily, the second connection area 30231 can be connected to the second blank area 30212 by welding, which not only makes the connection between the second pole ear 3023 and the second blank area 30212 firm, but also makes the second pole ear 3023 and the second blank area 30212 have good current flow capacity. The second pole ear 3023 can be connected to the second blank area 30212 by laser welding, so that the welding between the second pole ear 3023 and the second blank area 30212 has good welding quality, which is conducive to reducing the appearance of sharp objects such as welding slag and burrs, and helps to reduce the possibility of the second pole ear 3023 piercing the first pole piece 301.

[0099] The separator 303 is a component for isolating the stacked first pole piece 301 and the second pole piece 302, and is stacked between the adjacent first pole pieces 301 and the second pole pieces 302. Exemplarily, the separator 303 may be a separator. The embodiments of the present application have no particular restrictions on the type of separator, and any known porous separator with good chemical stability and mechanical stability may be selected.

[0100] As an example, the main material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics. The isolation membrane can be a single-layer film or a multi-layer composite film, without special restrictions. When the isolation membrane is a multi-layer composite film, the materials of each layer can be the same or different, without special restrictions. The isolation member 303 can be a separate component located between the first pole piece 301 and the second pole piece 302, or it can be attached to the surface of the first pole piece 301 and the second pole piece 302.

[0101] Exemplarily, the separator 303 may also be a solid electrolyte. The solid electrolyte is disposed between the first pole piece 301 and the second pole piece 302 , and plays the role of transmitting ions and isolating the first pole piece 301 from the second pole piece 302 .

[0102] The insulating layer 304 may be a structural layer with insulating properties. By making at least part of the insulating layer 304 located between the first pole piece 301 and the second blank area 30212 and covering the second connection area 30231 in the stacking direction of the first pole piece 301 and the second pole piece 302, there is not only a separator 303 between the second blank area 30212 and the first pole piece 301, but also an insulating layer 304 that can play an insulating and protective role, so that the second pole ear 3023 is not easy to penetrate the first pole piece 301, reducing the possibility of short circuit between the first pole piece 301 and the second pole piece 302, so that the electrode assembly 30 has good reliability, thereby helping to improve the reliability of the battery 2.

[0103] In some embodiments, the insulating layer 304 is used to block at least a portion of ions released from the first active material layer 3012 from being embedded in the second active material layer 3022 .

[0104] The insulating layer 304 blocks the ions released from the first active material layer 3012 and prevents these ions from being embedded in the second active material layer 3022 , so that lithium deposition is less likely to occur on the surface of the second electrode 302 , which is beneficial to improving the reliability of the electrode assembly 30 .

[0105] In some embodiments, the insulating layer 304 can be made of an insulating material, and the insulating layer 304 has a large resistance, which can completely block the transmission of part of the electrons in the second blank area 30212 and the first active material layer 3012, thereby reducing the occurrence of lithium precipitation. Exemplarily, the insulating layer 304 can be selected from one or a combination of several of an insulating glue layer, a ceramic insulating layer, and an insulating tape, which can effectively transmit electrons between the second blank area 30212 and the first active material layer 3012, thereby reducing the occurrence of lithium precipitation.

[0106] Exemplarily, the insulating layer 304 may include a polymer material, which includes at least one of styrene-butadiene rubber, polyacrylate, polyvinyl chloride, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene polymer, epoxy resin, butadiene-acrylonitrile polymer, polyurethane rubber, polymethyl acrylate and polyethyl acrylate.

[0107] In some embodiments, the insulating layer 304 can be formed by curing insulating glue. Since it is convenient to arrange the insulating glue between the first active material layer 3012 and the second blank area 30212, the insulating layer 304 is formed by curing the insulating glue, which is conducive to improving the production efficiency of the electrode assembly 30.

[0108] In some embodiments, Figure 7 As shown, the insulating layer 304 is attached to the first active material layer 3012 .

[0109] The insulating layer 304 is attached to the first active material layer 3012, and the insulating layer 304 may be disposed on the surface of the first active material layer 3012 away from the first current collector 3011, so that the insulating layer 304 can reduce the escape of ions from the first active material layer 3012. Exemplarily, the insulating layer 304 may be formed by curing an insulating glue applied to the surface of the first active material layer 3012 away from the first current collector 3011.

[0110] In some embodiments, in the stacking direction, the projection of the second blank area 30212 is located within the projection of the insulating layer 304 .

[0111] By configuring the projection of the second blank area 30212 in the stacking direction to fall within the projection of the insulating layer 304 in the stacking direction, the insulating layer 304 can cover the entire second blank area 30212, so that the insulating layer 304 has a better covering effect on the connection position between the second pole ear 3023 and the second blank area 30212, further reducing the possibility of the second pole ear 3023 piercing the first pole piece 301.

[0112] In some embodiments, the first pole piece 301, the second pole piece 302 and the isolation member 303 are wound along the winding direction; the second active material layer 3022 and the second blank area 30212 define a first recess 3024, and the first recess 3024 forms an opening along at least one end of the first direction X, and the first direction X is perpendicular to the winding direction; the second pole ear 3023 also includes a second extension area 30232 connected to the second connection area 30231, the second connection area 30231 is accommodated in the first recess 3024, and the second extension area 30232 protrudes from the second blank area 30212 along the first direction X.

[0113] The electrode assembly 30 forms a winding structure by winding the stacked first electrode sheet 301 , the second electrode sheet 302 , and the separator 303 along a winding direction.

[0114] Since the surface of the second coated area 30211 is provided with the second active material layer 3022, and the surface of the second blank area 30212 is not coated with the second active material layer 3022, the surface of the second blank area 30212 is recessed relative to the surface of the second active material layer 3022, and the second active material layer 3022 and the second blank area 30212 in the second pole piece 302 jointly form a first recess 3024.

[0115] By forming an opening at at least one end of the first recess 3024 along the first direction X, the second blank area 30212 is located at the end of the second pole piece 302 in the first direction X. The second extended area 30232 may be a portion of the second pole tab 3023 connected to the second connection area 30231. The second connection area 30231 is accommodated in the first recess 3024 and connected to the second blank area 30212. The second extended area 30232 protrudes from the second blank area 30212 along the first direction X. Figure 8 As shown, the second pole tab 3023 connected to the second blank area 30212 can extend outward, making it easier for the second pole tab 3023 to be connected to other components.

[0116] Among them, the first direction X is configured as a direction perpendicular to the winding direction of the first pole piece 301, the second pole piece 302 and the isolation member 303, so that the first direction X is the axial direction of the winding structure, which facilitates the connection between the second protruding area 30232 of the second blank area 30212 along the first direction X and the component located axially outside the electrode assembly 30.

[0117] In some embodiments, a second insulating layer 305 is disposed in the first recess 3024 , and the second insulating layer 305 covers the connection between the second electrode tab 3023 and the second blank area 30212 .

[0118] The second insulating layer 305 can be formed by placing insulating glue in the first concave portion 3024, so that the insulating glue forms the second insulating layer 305 covering the connection between the second electrode tab 3023 and the second blank area 30212. Fig. 9 As shown, the second insulating layer 305 formed by the insulating glue covers the connection between the second pole ear 3023 and the second blank area 30212, which not only increases the connection strength of the second pole ear 3023 and the second blank area 30212, but also enables the second insulating layer 305 to insulate and protect the connection between the second pole ear 3023 and the second blank area 30212, further making it difficult for the second pole ear 3023 to penetrate the first pole piece 301, reducing the possibility of short circuit between the first pole piece 301 and the second pole piece 302, thereby improving the reliability of the electrode assembly 30.

[0119] In some embodiments, Figure 7 and Fig.10As shown, the first pole piece 301 may also adopt a structure similar to that of the second pole piece 302, which also includes a first pole ear 3013, the first current collector 3011 includes a first coated area 30111 coated with a first active material layer 3012 and a first blank area 30112 not coated with the first active material layer 3012, the first pole ear 3013 is connected to the first blank area 30112, and a second insulating layer 305 formed by insulating glue is arranged on the first blank area 30112 to cover the connection between the first pole ear 3013 and the first blank area 30112, so that the negative first pole ear 3013 is not easy to penetrate the second pole piece 302, thereby reducing the possibility of short circuit between the first pole piece 301 and the second pole piece 302, thereby improving the reliability of the electrode assembly 30.

[0120] Some embodiments of the present application also provide a battery cell 7, such as Fig.11 As shown, the battery cell 7 includes a housing 20 and an electrode assembly 30 provided by the above technical solution, and the electrode assembly 30 is accommodated in the housing 20. Since the battery cell 7 includes the electrode assembly 30 provided by the above technical solution, the battery cell 7 has good reliability.

[0121] In some embodiments, the battery cell 7 also includes an insulating sheet 71, which is located on one side of the second active material layer 3022; the outer shell 20 includes a first electrode lead-out member 201, which is located on the side of the insulating sheet 71 away from the active material layer, and the insulating sheet 71 is provided with a first through hole 711, and the second electrode ear 3023 is connected to the first electrode lead-out member 201 through the first through hole 711.

[0122] The first electrode lead-out member 201 may be a device in the battery cell 7 for electrically connecting to an external device, and the battery cell 7 may conveniently output electric energy or charge through the first electrode lead-out member 201. For example, the first electrode lead-out member 201 may be a columnar structure or a sheet structure, and those skilled in the art may configure it according to actual conditions.

[0123] In some embodiments, the housing 20 may include a shell and two covers, the shell being a hollow structure with openings on opposite sides, and one cover correspondingly covering one opening of the shell and forming a sealed connection to form a sealed space for accommodating the electrode assembly 30 and the electrolyte. Exemplarily, two first electrode lead-out members 201 may be provided, and the two first electrode lead-out members 201 may serve as the positive electrode and the negative electrode of the battery cell 7, respectively, and the two first electrode lead-out members 201 may be installed on the same cover or on different covers.

[0124] The insulating sheet 71 may be a sheet-like component having insulating properties. Fig.12As shown, the first through hole 711 can be a hole-like structure opened on the insulating sheet 71 and penetrated along the thickness direction thereof. By arranging the insulating sheet 71 on one side of the second active material layer 3022 in the first direction X, the insulating sheet 71 can not only realize the insulation isolation between the second active material layer 3022 and the first electrode lead-out member 201, but also enable the second electrode tab 3023 extending along the first direction X to pass through the first through hole 711 and be connected to the first electrode lead-out member 201, thereby realizing the connection between the electrode assembly 30 and the first electrode lead-out member 201, and facilitating the battery 2 to output electrical energy to the outside.

[0125] In some embodiments, the insulating sheet 71 can be made of a polymer material, including at least one of styrene-butadiene rubber, polyacrylate, polyvinyl chloride, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene polymer, epoxy resin, butadiene-acrylonitrile polymer, polyurethane rubber, polymethyl acrylate and polyethyl acrylate, so that the insulating sheet 71 has good insulating properties.

[0126] By passing the second pole ear 3023 connected to the second blank area 30212 through the first through hole 711 of the insulating sheet 71, the inner wall of the first through hole 711 can support the second pole ear 3023, thereby reducing the flattening of the pole ear and the space occupied by the pole ear of the current collector, which is beneficial to improving the energy density of the battery cell 7.

[0127] In some embodiments, the battery cell 7 further includes a current collecting member 72 connected to the first electrode lead-out member 201 , the current collecting member 72 is disposed between the insulating sheet 71 and the first electrode lead-out member 201 , and the second electrode tab 3023 is connected to the current collecting member 72 through the first through hole 711 .

[0128] The current collecting member 72 may be a device for electrically connecting the second electrode tab 3023 to the first electrode lead-out member 201, and is configured as a conductive device. By disposing the current collecting member 72 between the insulating sheet 71 and the first electrode lead-out member 201, and connecting the second electrode tab 3023 and the first electrode lead-out member 201 to the current collecting member 72, the second electrode tab 3023 and the first electrode lead-out member 201 can be conveniently connected through the current collecting member 72.

[0129] Exemplarily, the current collecting component 72 can be connected to the first electrode lead-out member 201 by laser welding, so that the current collecting component 72 and the material can be melted together with the material of the first electrode lead-out member 201, which is not only beneficial to improve the connection strength between the current collecting component 72 and the first electrode lead-out member 201, but also beneficial to improve the current flow capacity at the connection between the current collecting component 72 and the first electrode lead-out member 201.

[0130] In some embodiments, Fig.13As shown, the current collecting member 72 is provided with a second through hole 7211 communicating with the first through hole 711 , and the second electrode tab 3023 passes through the first through hole 711 and the second through hole 7211 and is connected to a surface of the current collecting member 72 facing away from the insulating sheet 71 .

[0131] The second through hole 7211 can be a hole-like structure arranged on the current collecting component 72 and penetrating along the first direction X. It is arranged opposite to and connected to the first through hole 711 along the first direction X. The second pole ear 3023 extending into the first through hole 711 can pass through the second through hole 7211 and extend from the surface of the current collecting component 72 away from the insulating sheet 71, so that the second pole ear 3023 can be connected to the surface of the current collecting component 72 away from the insulating sheet 71.

[0132] Exemplarily, the portion of the second electrode tab 3023 extending from the surface of the current collecting member 72 away from the insulating sheet 71 can be connected to the surface of the current collecting member 72 away from the insulating sheet 71 by laser welding, so that the second electrode tab 3023 is firmly connected to the current collecting member 72.

[0133] In some embodiments, the current collecting component 72 includes a confluence portion 721 and a transition portion 722 connected to the confluence portion 721, the second through hole 7211 is opened in the confluence portion 721, the confluence portion 721 is located between the insulating sheet 71 and the first electrode lead-out member 201 and is connected to the second electrode tab 3023 and the first electrode lead-out member 201, and the transition portion 722 is bent toward the first electrode lead-out member 201 and is connected to the first electrode lead-out member 201.

[0134] The confluence portion 721 and the transition portion 722 are respectively different partial structures in the current collecting component 72, and the transition portion 722 is connected to the confluence portion 721. Among them, the confluence portion 721 is a portion of the current collecting component 72 connected to the plurality of second pole tabs 3023, and the second through hole 7211 is provided on the confluence portion 721, so that the electric energy output by the plurality of second pole tabs 3023 can be collected in the confluence portion 721 and output to the outside through the confluence portion 721, or the electric energy input from the outside can be input to the plurality of second pole tabs 3023 through the confluence portion 721. The transition portion 722 is a portion of the current collecting component 72 used to connect with the first electrode lead-out member 201, and is used to transmit the electric energy collected in the confluence portion 721 to the first electrode lead-out member 201, or to input the electric energy input from the outside into the confluence portion 721.

[0135] By disposing the busbar 721 between the insulating sheet 71 and the first electrode lead-out member 201 , it is convenient to connect the transition portion 722 connected to the busbar 721 to the first electrode lead-out member 201 .

[0136] In some embodiments, the adapter 722 is bent toward the first electrode lead-out member 201 and connected to the first electrode lead-out member 201. One end of the adapter 722 is connected to the confluence member 721, and the other end passes through the first through hole 711 and the second through hole 7211 in sequence, and then is bent toward and connected to the first electrode lead-out member 201. The end of the adapter 722 is bent and then connected to the first electrode lead-out member 201, so that a larger connection area can be obtained, which is conducive to improving the connection firmness between the adapter 722 and the first electrode lead-out member 201.

[0137] Exemplarily, the adapter 722 and the confluence part 721 may be an integrally formed structure. The adapter 722 and the confluence part 721 may be made by an integrally formed processing method such as stamping, so that the current collecting component 72 can be manufactured synchronously as a whole, which not only makes the processing and manufacturing of the current collecting component 72 convenient, but also reduces the connection steps; the adapter 722 and the confluence part 721 may also be made by machining a whole piece of blank by cutting or other mechanical processing methods, so that the current collecting component 72 has a lower processing difficulty and processing cost.

[0138] In some embodiments, there are multiple second electrode tabs 3023 , there are multiple first through holes 711 , the multiple first through holes 711 are arranged at intervals, and the multiple second electrode tabs 3023 pass through the multiple first through holes 711 respectively to connect to the first electrode lead-out member 201 .

[0139] By winding the second pole piece 302 into a plurality of coil structures and arranging the second pole ear 3023 on half of the coils of the second pole piece 302, a plurality of second pole ears 3023 are provided, so that the battery cell assembly can be discharged or charged smoothly.

[0140] By providing a plurality of first through holes 711, and the plurality of first through holes 711 are spaced apart along the winding direction of the second pole piece 302, the first through holes 711 correspond to the second pole ears 3023 one by one, so that the plurality of second pole ears 3023 pass through the plurality of first through holes 711 one by one and are connected to the first electrode lead-out member 201, which helps to reduce the occurrence of the plurality of second pole ears 3023 being entangled or adhered together.

[0141] Some embodiments of the present application further provide a battery 2, which includes a battery cell 7 provided by the above technical solution.

[0142] Some embodiments of the present application further provide an electrical device, which includes the battery 2 provided by the above technical solution, and the battery 2 is used to provide electrical energy.

[0143] Some embodiments of the present application provide an electrode assembly 30, which includes a first electrode sheet 301, a second electrode sheet 302, a separator 303 and an insulating layer 304, wherein the separator 303 is located between the first electrode sheet 301 and the second electrode sheet 302, and the separator 303, the first electrode sheet 301 and the second electrode sheet 302 are stacked and wound. The second electrode sheet 302 includes a second coating area 30211 coated with a second active material layer 3022 and a second blank area 30212 not coated with the second active material layer 3022, the second active material layer 3022 and the second blank area 30212 define a first concave portion 3024 with an opening at one end in the first direction X, a portion of the second electrode ear 3023 is located in the first concave portion 3024 and connected to the second blank area 30212, and another portion protrudes from the second blank area 30212 in the first direction X. The insulating layer 304 is attached to the first active material layer 3012 of the first electrode 301 and is used to block at least a portion of ions released from the first active material layer 3012 from being embedded in the second active material layer 3022 . The projection of the insulating layer 304 in the stacking direction is located at the projection of the second blank area 30212 in the stacking direction.

[0144] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. An electrode assembly, characterized in that: include: A first pole piece, comprising a first active material layer; A second pole piece, stacked with the first pole piece and having opposite polarity, the second pole piece comprising a second current collector, a second active material layer, and a second pole tab, the second current collector comprising a second coating area coated with the second active material layer and a second blank area not coated with the second active material layer, the second pole tab having a second connection area connected to the second blank area; An isolating member, used for isolating the first pole piece and the second pole piece; as well as An insulating layer, in the stacking direction of the first pole piece and the second pole piece, at least a portion of the insulating layer is located between the first pole piece and the second blank area and covers the second connecting area.

2. The electrode assembly according to claim 1, characterized in that: The insulating layer is attached to the first active material layer.

3. The electrode assembly according to claim 1, characterized in that: In the stacking direction, a projection of the second blank area is located within a projection of the insulating layer.

4. The electrode assembly according to claim 1, characterized in that: The first pole piece, the second pole piece and the separator are wound along a winding direction; The second active material layer and the second blank area define a first concave portion, wherein at least one end of the first concave portion forms an opening along a first direction, and the first direction is perpendicular to the winding direction; The second electrode tab further includes a second extending region connected to the second connecting region, the second connecting region is accommodated in the first recess, and the second extending region protrudes from the second blank region along the first direction.

5. The electrode assembly according to claim 1, characterized in that: A second insulating layer is disposed in the first recess, and the second insulating layer covers a connection between the second connecting area and the second blank area.

6. A battery cell, characterized in that: include: shell; The electrode assembly according to any one of claims 1 to 5, wherein the electrode assembly is accommodated in the housing.

7. The battery cell according to claim 6, characterized in that: The battery cell further includes an insulating sheet, and the insulating sheet is located on one side of the second active material layer; The housing includes a first electrode lead-out member, which is located on a side of the insulating sheet away from the active material layer. The insulating sheet is provided with a first through hole, and the second electrode tab passes through the first through hole and is connected to the first electrode lead-out member.

8. The battery cell according to claim 7, characterized in that: The battery cell further includes a current collecting member connected to the first electrode lead-out member, the current collecting member being disposed between the insulating sheet and the first electrode lead-out member, and the second electrode tab is connected to the current collecting member through the first through hole.

9. The battery cell according to claim 8, characterized in that: The current collecting member is provided with a second through hole communicating with the first through hole, and the second electrode tab passes through the first through hole and the second through hole and is connected to a surface of the current collecting member away from the insulating sheet.

10. The battery cell according to claim 9, characterized in that: The current collecting component includes a confluence portion and a transition portion connected to the confluence portion, the second through hole is opened in the confluence portion, the confluence portion is located between the insulating sheet and the first electrode lead-out member and is connected to the second electrode tab, and the transition portion is bent toward the first electrode lead-out member and connected to the first electrode lead-out member.

11. The battery cell according to claim 7, characterized in that: There are a plurality of second electrode tabs, there are a plurality of first through holes, the plurality of first through holes are arranged at intervals, and the plurality of second electrode tabs respectively pass through the plurality of first through holes to be connected to the first electrode lead-out member.

12. A battery, characterized in that: Comprising the battery cell according to any one of claims 6 to 11.

13. An electrical device, characterized in that: Comprising the battery of claim 12, the battery being used to provide electrical energy.

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