Battery monomer, battery device and electric device

Abstract

The invention provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell and an electrode assembly, the electrode assembly comprises pole pieces, a solid electrolyte and a first insulating part, the pole pieces comprise a first pole piece and a second pole piece, the first pole piece comprises a first pole piece main body and a first tab, and the first tab is connected to one side of the first pole piece main body along a first direction; the second pole piece comprises a second pole piece main body and a second tab, the second tab is connected to one side of the second pole piece main body along the first direction, the first insulating part comprises a first insulator and a second insulator, the first insulator is formed on the surface of the first tab along the thickness direction of the pole piece, and the second insulator is formed on the surface of the second tab along the thickness direction of the pole piece. The second insulator is formed on the surface of the second tab along the thickness direction of the pole piece and is arranged at one end, close to the second tab, of the first pole piece main body along the first direction. According to the invention, the reliability of the battery monomer can be effectively improved.

Description

Technical Field

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

[0002] With the development of new energy technology, batteries are used more and more widely, for example, in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and electric tools, etc.

[0003] In the development of battery technology, how to improve the reliability of battery cells is a continuous research direction in battery technology. Summary of the invention

[0004] In view of the above problems, the present application provides a battery cell, a battery device and an electrical device, which can effectively improve the reliability of the battery cell.

[0005] In the first aspect, an embodiment of the present application provides a battery cell, which includes a shell and an electrode assembly, the electrode assembly being accommodated in the shell, the electrode assembly including pole pieces, a solid electrolyte and a first insulating component, the pole pieces including a first pole piece and a second pole piece, the first pole piece and the second pole piece being alternately arranged along the thickness direction of the pole piece and having opposite polarities, and the solid electrolyte being arranged between the first pole piece and the second pole piece.

[0006] The first pole piece includes a first pole piece body and a first pole ear, the first pole ear is connected to one side of the first pole piece body along a first direction, the second pole piece includes a second pole piece body and a second pole ear, the second pole ear is connected to one side of the second pole piece body along the first direction, and the first direction is perpendicular to the thickness direction of the pole piece.

[0007] The first insulating component includes a first insulator and a second insulator. The first insulator is arranged at one end of the second pole piece body close to the first pole ear along the first direction, and is used to insulate the first pole ear and the second pole piece body. The second insulator is arranged at one end of the first pole piece body close to the second pole ear along the first direction, and is used to insulate the second pole ear and the first pole piece body.

[0008] The first insulator is formed on the surface of the first pole tab along the thickness direction of the pole piece, and the second insulator is formed on the surface of the second pole tab along the thickness direction of the pole piece.

[0009] The above technical solution introduces a first insulating component, and the first insulator can isolate and protect the first pole ear and the second pole piece body to reduce the risk of short circuit caused by overlapping the first pole ear and the second pole piece body; the second insulator can isolate and protect the second pole ear and the first pole piece body to reduce the risk of short circuit caused by overlapping the second pole ear and the first pole piece body, which can effectively improve the reliability and product yield of the battery cell. In addition, it can not only reduce the difficulty of setting the first insulator and the second insulator, but also improve the structural compactness of the electrode assembly, which helps to improve the energy density of the battery cell.

[0010] In some embodiments of the first aspect, a projection of the first insulator along the first direction covers a projection of the second pole piece body along the first direction; and / or a projection of the second insulator along the first direction covers a projection of the first pole piece body along the first direction.

[0011] The first insulator is able to completely cover one end of the second pole piece body close to the first pole ear along the first direction, thereby further improving the effect of the first insulator isolating and protecting the first pole ear and the second pole piece body. The second insulator is able to completely cover one end of the first pole piece body close to the second pole ear along the first direction, thereby further improving the effect of the second insulator isolating and protecting the second pole ear and the first pole piece body.

[0012] In some embodiments of the first aspect, the first electrode body includes a first current collector, a first active material layer and a second active material layer, the first active material layer and the second active material layer are respectively coated on the two side surfaces of the first current collector opposite to each other along the thickness direction, and the first insulator is connected to the side of the first electrode ear close to the first active material layer, and protrudes from the side surface of the first active material layer facing away from the first current collector.

[0013] The second pole piece body includes a second current collector, a third active material layer and a fourth active material layer, the third active material layer and the fourth active material layer are respectively connected to the two opposite surfaces of the second current collector along the thickness direction, the second insulator is connected to the side of the second pole ear close to the third active material layer, and protrudes from the side of the third active material layer facing away from the second current collector. The first active material layer and the third active material layer are arranged oppositely, and the second active material layer and the fourth active material layer are arranged oppositely.

[0014] The above technical solution provides a first insulator only on one side of the first pole ear along the thickness direction, and a second insulator only on one side of the second pole ear along the thickness direction, so that the first pole piece and the second pole piece form a spliced ​​assembly structure, which helps to simplify the preparation process of the electrode assembly and reduce costs.

[0015] In some embodiments of the first aspect, a projection of the second active material layer along the thickness direction partially overlaps with a projection of the first insulator along the thickness direction; and / or a projection of the fourth active material layer along the thickness direction partially overlaps with a projection of the second insulator along the thickness direction.

[0016] The second active material layer can fill the gap between the first insulator and the first electrode tab to a certain extent, thereby improving the overall structural compactness and stability of the electrode assembly. The fourth active material layer can fill the gap between the second insulator and the second electrode tab to a certain extent, thereby improving the overall structural compactness and stability of the electrode assembly.

[0017] In some embodiments of the first aspect, a first size L1 of the first active material layer along the first direction, a second size L2 of the second active material layer along the first direction, and a third size L3 of the first insulator along the first direction satisfy the relationship: L2≤L1+L3.

[0018] The above technical solution can, to a certain extent, avoid the situation where the size of the second active material layer along the first direction is too large, resulting in the effective size of the first electrode tab being too small, thereby reducing the difficulty of processing and assembling the electrode assembly.

[0019] In some embodiments of the first aspect, the first dimension L1 satisfies the relationship: 20 mm ≤ L1 ≤ 2000 mm, and the third dimension L3 satisfies the relationship: 15 um ≤ L3 ≤ 2000 um.

[0020] The above technical solution can reduce the influence of the first insulator on the energy density of the battery cell while ensuring that the first insulator has a reliable insulating spacing effect by setting the first size L1 and the third size L3 within the above range.

[0021] In some embodiments of the first aspect, the first size L1 satisfies the relationship: 40 mm ≤ L1 ≤ 1000 mm, and the third size L3 satisfies the relationship: 30 um ≤ L3 ≤ 1000 um, which can further improve the balance between the reliability and energy density of the battery cell.

[0022] In some embodiments of the first aspect, a fourth size L4 of the third active material layer along the first direction, a fifth size L5 of the fourth active material layer along the first direction, and a sixth size L6 of the second insulator along the first direction satisfy the relationship: L5≤L4+L6.

[0023] The above technical solution can, to a certain extent, avoid the situation where the size of the fourth active material layer along the first direction is too large, resulting in the effective size of the second electrode tab being too small, thereby reducing the difficulty of processing and assembling the electrode assembly.

[0024] In some embodiments of the first aspect, the fourth dimension L4 satisfies the relationship: 20 mm ≤ L4 ≤ 2000 mm, and the sixth dimension L6 satisfies the relationship: 15 um ≤ L6 ≤ 2000 um.

[0025] The above technical solution can reduce the influence of the second insulator on the energy density of the battery cell while ensuring that the second insulator has a reliable insulating spacing effect by setting the fourth dimension L4 and the sixth dimension L6 within the above range.

[0026] In some embodiments of the first aspect, the fourth dimension L4 satisfies the relationship: 40 mm ≤ L4 ≤ 1000 mm, and the sixth dimension L6 satisfies the relationship: 30 um ≤ L6 ≤ 1000 um, which can further improve the balance between the reliability and energy density of the battery cell.

[0027] In some embodiments of the first aspect, a first size L1 of the first active material layer along the first direction and a fourth size L4 of the third active material layer along the first direction satisfy the relationship: -2 mm ≤ L1 - L4 ≤ 2 mm.

[0028] The above technical solution can reduce the gap inside the electrode assembly and improve the reliability of the electrode assembly by setting the difference between the first size L1 and the fourth size L4 within the above range.

[0029] In some embodiments of the first aspect, the first dimension L1 and the fourth dimension L4 satisfy the relationship: -0.5 mm≤L1-L4≤0.5 mm.

[0030] The gap inside the electrode assembly can be further reduced to further improve the reliability of the electrode assembly.

[0031] In some embodiments of the first aspect, a surface of the first insulator along the thickness direction away from the first current collector is flush with a surface of the fourth active material layer along the thickness direction away from the second current collector; and / or a surface of the second insulator along the thickness direction away from the second current collector is flush with a surface of the first active material layer along the thickness direction away from the first current collector.

[0032] It can effectively improve the structural consistency and compactness of the electrode assembly, and help to further improve the reliability of the electrode assembly.

[0033] In some embodiments of the first aspect, the solid electrolyte includes a first electrolyte layer and a second electrolyte layer, and the first electrolyte layer and the second electrolyte layer are respectively coated on two side surfaces of the second electrode body opposite to each other along the thickness direction.

[0034] By directly coating the solid electrolyte on the second pole piece body, the preparation process of the electrode assembly can be simplified, which helps to reduce costs.

[0035] In some embodiments of the first aspect, the first pole piece and the second pole piece are wound along a winding direction, and the first pole tab and the second pole tab are arranged opposite to each other along the first direction. The first pole tab is wound along the winding direction and includes a plurality of turns of the first pole tab layer, the second pole tab is wound along the winding direction and includes a plurality of turns of the second pole tab layer, the first insulator is arranged between two adjacent turns of the first pole tab layer, and the second insulator is arranged between two adjacent turns of the second pole tab layer.

[0036] The above technical solution can greatly reduce the risk of short circuit of the electrode assembly with a winding structure, improve the shortcomings of the solid-state battery cells with the electrode assembly with a winding structure, and effectively improve the economic benefits of the solid-state battery cells with the electrode assembly with a winding structure.

[0037] In some embodiments of the first aspect, the battery cell further includes a supporting component, and the first pole piece and the second pole piece are wound around the supporting component.

[0038] The support component is used to support the first pole piece and the second pole piece to reduce the risk of the first pole piece and the second pole piece deforming or collapsing inwardly under the action of external force, thereby improving the reliability of the battery cell.

[0039] In some embodiments of the first aspect, a side surface of the first insulator away from the second pole piece body along the first direction is flush with a side end surface of the support component close to the first pole lug along the first direction; and / or a side surface of the second insulator away from the first pole piece body along the first direction is flush with a side end surface of the support component close to the second pole lug along the first direction. The structural consistency of the electrode assembly can be improved, and the difficulty of processing or assembling the electrode assembly can be reduced.

[0040] In some embodiments of the first aspect, in the winding direction, both ends of the second pole piece exceed both ends of the first pole piece. The electrode assembly also includes a second insulating component, which is connected to both ends of the first pole piece along the winding direction and is used to insulate the two ends of the first pole piece along the winding direction from the second pole piece.

[0041] The above technical solution can further reduce the risk of short circuit between the first pole piece and the second pole piece by introducing the second insulating component, so as to further improve the reliability of the battery cell.

[0042] In a second aspect, the present application provides a battery device, which includes a battery cell provided by any embodiment of the first aspect.

[0043] In a third aspect, the present application provides an electrical device, comprising a battery cell provided by any embodiment of the first aspect or a battery device provided by any embodiment of the second aspect, wherein the battery cell or the battery device is used to store or provide electrical energy.

[0044] 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

[0045] 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: Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application; Figure 2 A schematic diagram of an exploded structure of a battery device provided in some embodiments of the present application; Figure 3 A schematic diagram of the structure of a battery module provided in some embodiments of the present application; Figure 4 A schematic diagram of an exploded structure of a battery cell provided in some embodiments of the present application; Figure 5 A cross-sectional schematic diagram of an electrode assembly of a battery cell provided in some embodiments of the present application; Figure 6 A schematic diagram of the structure of a first pole piece and a second pole piece of a battery cell provided in some embodiments of the present application; Figure 7 A schematic diagram of a partial structure of a first pole piece and a second pole piece of a battery cell provided in some embodiments of the present application; Figure 8 A cross-sectional schematic diagram of an electrode assembly of a battery cell provided in some embodiments of the present application; Fig. 9 A schematic diagram of the winding structure of a first pole piece and a second pole piece of a battery cell provided in some embodiments of the present application.

[0046] The reference numerals in the specific implementation manner are as follows: 1. Vehicle; 2. Battery device; 3. Controller; 4. Motor; 5. Box; 5a. First box; 5b. Second box; 6. Battery module; 7. Battery cell; 10. Shell; 20. Electrode assembly; 21, first pole piece; 211, first pole piece body; 2111, first current collector; 2112, first active material layer; 2113, second active material layer; 212, first pole ear; 22, second pole piece; 221, second pole piece body; 2211, second current collector; 2212, third active material layer; 2213, fourth active material layer; 222, second pole ear; 23. solid electrolyte; 231. first electrolyte layer; 232. second electrolyte layer; 24, first insulating component; 241, first insulator; 242, second insulator; 30. Support components; 40. A second insulating member; X, thickness direction; Y, first direction; V, winding direction. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0048] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] The term “plurality” used in this application refers to two or more (including two).

[0054] In the present application, the term "parallel" includes not only the absolutely parallel situation, but also the roughly parallel situation conventionally recognized in engineering; meanwhile, "vertical" includes not only the absolutely vertical situation, but also the roughly vertical situation conventionally recognized in engineering.

[0055] With the development of new energy technology, batteries are used more and more widely, for example, in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and electric tools, etc.

[0056] In the development of battery technology, how to improve the reliability of battery cells is a continuous research direction in battery technology.

[0057] In the related art, the solid electrolyte of a solid-state battery cell can insulate and isolate the positive and negative electrodes. Therefore, a solid-state battery cell is usually not provided with an isolation film to isolate the positive and negative electrodes. However, the solid electrolyte is sensitive to mechanical stress. During the densification process such as compaction or hot pressing of the electrode assembly, or when the battery cell is vibrated or impacted during use, the solid electrolyte located at the edge of the electrode is prone to damage; at the same time, the positive electrode ear is prone to overlap with the negative electrode collector of the negative electrode under the action of mechanical stress, or the negative electrode ear is prone to overlap with the positive electrode collector of the positive electrode under the action of mechanical stress, thereby causing a short circuit risk and seriously affecting the reliability of the battery cell.

[0058] Based on the above considerations, the present application designs a battery cell, which includes a shell and an electrode assembly. The electrode assembly is accommodated in the shell, and the electrode assembly includes pole pieces, a solid electrolyte and a first insulating component. The pole pieces include a first pole piece and a second pole piece. The first pole piece and the second pole piece are staggered along the thickness direction of the pole piece and have opposite polarities, and the solid electrolyte is arranged between the first pole piece and the second pole piece.

[0059] The first pole piece includes a first pole piece body and a first pole ear, the first pole ear is connected to one side of the first pole piece body along a first direction, the second pole piece includes a second pole piece body and a second pole ear, the second pole ear is connected to one side of the second pole piece body along the first direction, and the first direction is perpendicular to the thickness direction of the pole piece.

[0060] The first insulating component includes a first insulator and a second insulator. The first insulator is arranged at one end of the second pole piece body close to the first pole ear along the first direction, and is used to insulate the first pole ear and the second pole piece body. The second insulator is arranged at one end of the first pole piece body close to the second pole ear along the first direction, and is used to insulate the second pole ear and the first pole piece body.

[0061] The above technical solution introduces a first insulating component. The first insulator can isolate and protect the first pole ear and the second pole piece body to reduce the risk of short circuit caused by overlapping the first pole ear and the second pole piece body; the second insulator can isolate and protect the second pole ear and the first pole piece body to reduce the risk of short circuit caused by overlapping the second pole ear and the first pole piece body, which can effectively improve the reliability and product yield of the battery cell.

[0062] The battery cells described in the embodiments of the present application are suitable for battery devices and electrical equipment using battery devices. Electrical equipment may be equipment that uses a battery device as a power source or various energy storage systems that use a battery device as an energy storage element. Electrical equipment may be, but is not limited to, mobile phones, tablets, laptops, electric toys, electric tools, battery cars, electric cars, ships, spacecraft, and the like. Among them, electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like, and spacecraft may include airplanes, rockets, space shuttles, and spacecraft, and the like.

[0063] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0064] Figure 1 A schematic diagram of the structure of a vehicle provided for some embodiments of the present application.

[0065] like Figure 1As shown, a battery device 2 is disposed inside the vehicle 1, and the battery device 2 may be disposed at the bottom, head, or tail of the vehicle 1. The battery device 2 may be used to power the vehicle 1, for example, the battery device 2 may be used as an operating power source for the vehicle 1.

[0066] The vehicle 1 may further include a controller 3 and a motor 4 , wherein the controller 3 is used to control the battery device 2 to supply power to the motor 4 , for example, to meet the power requirements of starting, navigating and driving the vehicle 1 .

[0067] In some embodiments of the present application, the battery device 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.

[0068] Figure 2 A schematic diagram of an exploded structure of a battery device provided in some embodiments of the present application.

[0069] In some embodiments, the battery device 2 may include one or more battery cell assemblies to provide voltage and capacity.

[0070] A battery cell assembly may include a plurality of battery cells ( Figure 2 (not shown), multiple battery cells are connected in series, in parallel or in mixed connection through a busbar component. Mixed connection means that multiple battery cells are connected in series and in parallel.

[0071] 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.

[0072] As an example, 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 storage battery cells, etc.

[0073] As an example, the battery cell may be 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 cell, such as a hexagonal battery cell.

[0074] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells; as an example, the battery cell assembly may be a battery module 6, and the battery module 6 is formed by arranging and fixing a plurality of battery cells to form an independent module. As an example, the battery module 6 may be formed by bundling a plurality of battery cells by a cable tie.

[0075] In some embodiments, the battery device 2 may be a battery pack, which includes a case 5 and one or more battery cell assemblies, and the battery cell assemblies are accommodated in the case 5. As an example, the battery cell assembly may be a battery module 6, and the battery cell assembly may be accommodated in the case by fixing the battery module 6 in the case. As an example, the battery cell assembly may also be accommodated in the case by directly fixing a plurality of battery cells to the case.

[0076] In some embodiments, the box 5 is used to accommodate battery cells, and the box 5 can have various structures.

[0077] In some embodiments, the box 5 may include a first box 5a and a second box 5b. The first box 5a and the second box 5b are buckled together to form a closed space inside the box 5 to accommodate the battery monomer assembly. The closed space here means covering or closing, which can be sealed or unsealed. The first box can be a top cover or a bottom plate.

[0078] In some embodiments, the box body 5 may include a top cover, a frame and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that a closed space is formed inside the box body to accommodate the battery cell assembly. As an example, the frame may include a plurality of side beams.

[0079] In some embodiments, the box 5 can be used as a part of the chassis structure of the vehicle. For example, part of the box 5 can become at least a part of the floor of the vehicle, or part of the box 5 can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0080] In some embodiments, the battery device 2 may be an energy storage device.

[0081] Energy storage devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems or temporary power supply systems. Energy storage devices can store electrical energy as needed and output it at the appropriate time. For example, energy storage devices can store electrical energy when electricity consumption is low, and provide electrical energy to relevant users or electrical equipment during peak electricity consumption.

[0082] In some embodiments, the energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0083] Figure 3 A schematic structural diagram of a battery module provided in some embodiments of the present application.

[0084] In some embodiments, Figure 3 As shown, 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.

[0085] 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. There can be one or more busbar components, each of which is used to electrically connect at least two battery cells 7.

[0086] An embodiment of the present application provides a battery cell, which includes a housing and an electrode assembly accommodated in the housing.

[0087] In some embodiments, the shell may be a steel shell, an aluminum shell, or a composite metal shell (such as a copper-aluminum composite shell).

[0088] The housing may be a hollow structure, wherein a receiving cavity for receiving the electrode assembly and the electrolyte is formed inside the housing.

[0089] In some embodiments, the housing of the battery cell is a cylindrical housing, a square housing, a prismatic housing, or a housing of other shapes.

[0090] In some embodiments, the housing includes a shell and an end cap, the shell having an opening, and the end cap is connected to the shell and covers the opening; The housing is a component used to cooperate with the end cover to form an internal cavity of the battery cell. The formed internal cavity can be used to accommodate the electrode assembly, electrolyte and other components.

[0091] The housing and the end cap may be separate components. For example, an opening may be provided on the housing, and the end cap may be closed at the opening to form an internal cavity of the battery cell.

[0092] The shell can be of various shapes and sizes, such as a rectangular parallelepiped or a cylindrical shape. Specifically, the shape of the shell can be determined according to the specific shape and size of the electrode assembly. The shell can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0093] The shape of the end cap can be adapted to the shape of the shell to match the shell. The material of the end cap can be the same as or different from the material of the shell. Optionally, the end cap can be made of a material with a certain hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.), so that the end cap is not easily deformed when squeezed and collided, so that the battery cell can have a higher structural strength and the reliability performance can also be improved.

[0094] The end cover is connected to the shell by welding, bonding, clamping or other methods.

[0095] The shell may be open at one end or at both ends. In some examples, the shell may be a structure with one end open, and one end cap is provided and covers the shell. In other examples, the shell may be a structure with two ends open, and two end caps are provided, and the two end caps cover the two openings of the shell respectively.

[0096] The electrode assembly is the part in the battery cell where the electrochemical reaction occurs. One or more electrode assemblies may be contained in the housing.

[0097] In some embodiments, the electrode assembly includes a positive electrode sheet and a negative electrode sheet, and the positive electrode sheet has opposite polarity to the negative electrode sheet.

[0098] In some embodiments, the positive electrode sheet may include a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector.

[0099] As an example, the positive electrode current collector has two surfaces opposite to each other in its thickness direction, and the positive electrode film layer is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.

[0100] As an example, the positive electrode current collector may be a metal foil, a conductive polymer material, a carbon material or a composite current collector. For example, as the metal foil, a pure metal, an alloy, a surface-treated metal may be used, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloy, titanium or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0101] As an example, the positive electrode film layer includes a positive electrode active material, and 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 traditional materials that can be used as positive electrode active materials for batteries can also be used. These positive electrode active materials can be used alone or in combination of two or more. Among them, 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 NCM523 )、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 0.8 Co 0.15 Al 0.05 O2) and at least one of its modified compounds. The modified compound refers to a substance obtained by modifying the above substances by means of doping or coating.

[0102] In some embodiments, the negative electrode sheet may include a negative electrode current collector.

[0103] As an example, the negative electrode current collector may be a metal foil, a conductive polymer material, a carbon material or a composite current collector. For example, as the metal foil, a pure metal, an alloy, a surface-treated metal may be used, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloy, titanium or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0104] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector.

[0105] As an example, the negative electrode current collector has two surfaces opposite to each other in its thickness direction, and the negative electrode film layer is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.

[0106] As an example, the negative electrode film layer includes a negative electrode active material, and the negative electrode active material can adopt a negative electrode active material for a battery cell 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, lithium titanate, etc. The silicon-based material can 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 can 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 cells can also be used. These negative electrode active materials can be used alone or in combination of two or more.

[0107] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0108] In some embodiments, the electrode assembly further includes a solid electrolyte, which is disposed between the positive electrode sheet and the negative electrode sheet and serves to transmit ions and isolate the positive and negative electrodes.

[0109] In some embodiments, the solid electrolyte includes a polymer solid electrolyte, an inorganic solid electrolyte, and a composite solid electrolyte.

[0110] As examples, the polymer of the polymer solid electrolyte may include polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, a polyionic liquid, cellulose, and the like.

[0111] 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 phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0112] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0113] In some embodiments, the electrode assembly may be a wound structure, a laminated structure, or a mixed structure of a wound structure and a laminated structure.

[0114] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0115] In some embodiments, the electrode assembly is a laminate structure.

[0116] As an example, multiple positive electrode sheets and multiple negative electrode sheets can be provided respectively, and multiple positive electrode sheets and multiple negative electrode sheets are alternately stacked. As an example, multiple positive electrode sheets can be provided, and the negative electrode sheet is folded to form multiple stacked folded sections, and a positive electrode sheet is sandwiched between adjacent folded sections.

[0117] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of folded sections that are stacked.

[0118] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0119] In some embodiments, the positive electrode current collector may include a positive electrode ear, and the negative electrode current collector may include a negative electrode ear. The positive electrode ear and the negative electrode ear can be used to transmit current. As an example, at least a portion of the positive electrode ear is not coated with the positive electrode film layer, and at least a portion of the negative electrode ear is not coated with the negative electrode film layer.

[0120] In some embodiments, the electrode assembly is a winding structure. The positive electrode ear is wound into multiple turns along the winding direction. Optionally, the end of the positive electrode ear is bent by a flattening or smoothing process to form a multi-layer structure stacked in the axial direction of the electrode assembly. Optionally, the positive electrode ear is annular.

[0121] In some embodiments, the negative electrode ear is wound into multiple turns along the winding direction. Optionally, the end of the negative electrode ear is bent by a flattening or smoothing process to form a multi-layer structure stacked in the axial direction of the electrode assembly. The negative electrode ear is annular.

[0122] In some embodiments, the electrode assembly includes an electrode body. As an example, the electrode body includes a positive electrode film layer, a portion of a positive electrode current collector covered with the positive electrode film layer, a negative electrode film layer, and a portion of a negative electrode current collector covered with the negative electrode film layer.

[0123] The positive electrode ear and the negative electrode ear can be led out from the same end of the electrode body, or can be led out from opposite ends of the electrode body.

[0124] In some embodiments, the battery cell includes a positive electrode lead-out portion and a negative electrode lead-out portion, the positive electrode lead-out portion is electrically connected to the positive electrode sheet, and the negative electrode lead-out portion is electrically connected to the negative electrode sheet.

[0125] The positive electrode lead-out portion and the negative electrode lead-out portion are used to be electrically connected to an external circuit to realize charging or discharging of the battery cell.

[0126] In some embodiments, the positive electrode lead-out portion includes a positive electrode terminal, at least a portion of which is exposed to the outside of the battery cell so as to be connected to the busbar component.

[0127] As an example, the positive terminal may be an independently formed component that is mounted on the housing. Alternatively, the positive terminal may also be a part of the housing.

[0128] In some examples, the positive terminal is directly connected to the positive electrode sheet; in other examples, the positive terminal and the positive electrode sheet are indirectly connected through other conductive structures, such as a positive electrode adapter.

[0129] In some embodiments, the positive terminal is connected to the end cap by welding, riveting, clamping or other means.

[0130] In some embodiments, the negative electrode lead-out portion includes a negative electrode terminal, at least a portion of which is exposed to the outside of the battery cell so as to be connected to the busbar component.

[0131] As an example, the negative terminal may be an independently formed component that is mounted on the housing. Alternatively, the negative terminal may also be a part of the housing.

[0132] In some examples, the negative electrode terminal is directly connected to the negative electrode sheet; in other examples, the negative electrode lead-out portion further includes other conductive structures connecting the negative electrode terminal and the negative electrode sheet, such as a negative electrode adapter sheet.

[0133] In some embodiments, the negative terminal is connected to the end cap by welding, riveting, clamping or other means.

[0134] Figure 4 A schematic diagram of an exploded structure of a battery cell provided in some embodiments of the present application, Figure 5 A schematic cross-sectional view of an electrode assembly of a battery cell provided in some embodiments of the present application, Figure 6 A schematic diagram of the structure of a first pole piece and a second pole piece of a battery cell provided in some embodiments of the present application, Figure 7 A schematic diagram of the partial structure of the cooperation between a first pole piece and a second pole piece of a battery cell provided in some embodiments of the present application.

[0135] Continue to refer Figures 4 to 7 The embodiment of the present application provides a battery cell 7, which includes a shell 10 and an electrode assembly 20. The electrode assembly 20 is accommodated in the shell 10. The electrode assembly 20 includes a pole piece, a solid electrolyte 23 and a first insulating component 24. The pole piece includes a first pole piece 21 and a second pole piece 22. The first pole piece 21 and the second pole piece 22 are staggered along the thickness direction X of the pole piece and have opposite polarities. The solid electrolyte 23 is arranged between the first pole piece 21 and the second pole piece 22.

[0136] The first pole piece 21 includes a first pole piece body 211 and a first pole ear 212, the first pole ear 212 is connected to one side of the first pole piece body 211 along the first direction Y, the second pole piece 22 includes a second pole piece body 221 and a second pole ear 222, the second pole ear 222 is connected to one side of the second pole piece body 221 along the first direction Y, and the first direction Y is perpendicular to the thickness direction X of the pole piece.

[0137] The first insulating component 24 includes a first insulator 241 and a second insulator 242. The first insulator 241 is arranged at one end of the second pole piece body 221 close to the first pole ear 212 along the first direction Y, and is used to insulate the first pole ear 212 and the second pole piece body 221. The second insulator 242 is arranged at one end of the first pole piece body 211 close to the second pole ear 222 along the first direction Y, and is used to insulate the second pole ear 222 and the first pole piece body 211.

[0138] One of the first electrode sheet 21 and the second electrode sheet 22 is a positive electrode sheet, and the other is a negative electrode sheet. The related structures of the positive electrode sheet and the negative electrode sheet refer to the above description, which will not be repeated here.

[0139] The electrode assembly 20 may be a wound structure, a laminated structure, or a mixed structure of a wound structure and a laminated structure.

[0140] As an example, the electrode assembly 20 is a winding structure, and the first pole piece 21 and the second pole piece 22 are wound into a winding structure. In the winding structure, the first pole piece 21 and the second pole piece 22 are arranged adjacent to each other along the thickness direction X of the pole piece, which means that multiple turns of the first pole piece 21 and multiple turns of the second pole piece 22 are alternately stacked in sequence.

[0141] As an example, the electrode assembly 20 is a laminated structure, and a plurality of first pole pieces 21 and a plurality of second pole pieces 22 may be provided respectively, and a plurality of first pole pieces 21 and a plurality of second pole pieces 22 are alternately stacked. In the laminated structure, the first pole piece 21 and the second pole piece 22 are adjacently arranged along the thickness direction X of the pole piece, which means that a plurality of first pole pieces 21 and a plurality of second pole pieces 22 are alternately stacked in sequence.

[0142] The solid electrolyte 23 can be arranged in a variety of ways.

[0143] As an example, the solid electrolyte 23 may be coated on opposite sides of the first pole piece 21 along the thickness direction X, and then the first pole piece 21 and the second pole piece 22 are assembled so that the solid electrolyte 23 is connected between the first pole piece 21 and the second pole piece 22 .

[0144] As an example, the solid electrolyte 23 may be coated on opposite sides of the second pole piece 22 along the thickness direction X, and then the first pole piece 21 and the second pole piece 22 are assembled to connect the solid electrolyte 23 between the first pole piece 21 and the second pole piece 22 .

[0145] As an example, the solid electrolyte 23 may be coated on both sides of the first pole piece 21 opposite to each other along the thickness direction X, and the solid electrolyte 23 may be coated on both sides of the second pole piece 22 opposite to each other along the thickness direction X, and then the first pole piece 21 and the second pole piece 22 may be assembled so that the solid electrolyte 23 is connected between the first pole piece 21 and the second pole piece 22.

[0146] The first pole piece 21 may include a first current collector 2111 and a first film layer arranged on at least one surface of the first current collector 2111, the portion of the first current collector 2111 not provided with the first film layer constitutes a first pole lug 212, and the portion of the first current collector 2111 covered with the first film layer and the first film layer constitute a first pole piece body 211.

[0147] The second pole piece 22 may include a second current collector 2211 and a second film layer arranged on at least one surface of the second current collector 2211 , the portion of the second current collector 2211 not provided with the second film layer constitutes a second pole lug 222 , and the portion of the second current collector 2211 covered with the second film layer and the second film layer constitute a second pole piece body 221 .

[0148] It is understandable that the first pole ear 212 is easily deformed or moved in a direction close to the second pole piece body 221 under the action of mechanical stress, so that the first pole ear 212 and the second pole piece body 221 overlap and cause a risk of short circuit. The second pole ear 222 is easily deformed or moved in a direction close to the first pole piece body 211 under the action of mechanical stress, so that the second pole ear 222 and the first pole piece body 211 overlap and cause a risk of short circuit.

[0149] The first insulator 241 is disposed at one end of the second pole piece body 221 along the first direction Y close to the first pole ear 212 . There are many specific ways to dispose the first insulator 241 .

[0150] As an example, the first insulator 241 can be connected to the second pole piece body 221 and located on the side of the first pole ear 212 close to the second pole piece body 221, and the first insulator 241 and the first pole ear 212 are spaced apart, that is, there is a gap between the first insulator 241 and the first pole ear 212.

[0151] As an example, the first insulator 241 may also be connected to both the first pole tab 212 and the second pole piece body 221. In other words, the first insulator 241 is connected between the first pole tab 212 and the second pole piece body 221.

[0152] The second insulator 242 is disposed at one end of the first pole piece body 211 along the first direction Y close to the second pole ear 222 . There are many specific ways to dispose the second insulator 242 .

[0153] As an example, the second insulator 242 can be connected to the first pole piece body 211 and located on the side of the second pole ear 222 close to the first pole piece body 211, and the second insulator 242 and the second pole ear 222 are spaced apart, that is, there is a gap between the second insulator 242 and the second pole ear 222.

[0154] As an example, the second insulator 242 may also be connected to both the second pole tab 222 and the first pole piece body 211. In other words, the second insulator 242 is connected between the second pole tab 222 and the first pole piece body 211.

[0155] The material of the first insulating component 24 includes but is not limited to various organic insulating materials such as epoxy acrylate, polyurethane acrylate, resin glue, rubber, etc., and also includes but is not limited to various inorganic insulating materials such as mica, asbestos, etc., and insulating materials formed by mixing the above organic insulating materials and the above inorganic insulating materials.

[0156] Even if the first pole lug 212 is deformed or moved in a direction close to the second pole piece body 221 under the action of mechanical stress, the first insulator 241 can provide insulating support for the first pole lug 212 , thereby reducing the risk of overlap between the first pole lug 212 and the second pole piece body 221 .

[0157] Even if the second pole lug 222 is deformed or moved in a direction close to the first pole piece body 211 under the action of mechanical stress, the second insulator 242 can provide insulating support for the second pole lug 222 , thereby reducing the risk of overlap between the first pole lug 212 and the second pole piece body 221 .

[0158] In this way, the introduction of the first insulating component 24 can reduce the risk of short circuit between the first pole piece 21 and the second pole piece 22. During the densification process such as compaction or hot pressing of the electrode assembly 20, the scrap rate of the electrode assembly 20 can be reduced, which helps to improve the product yield of the battery cell 7. During the use of the battery cell 7, the reliability of the battery cell 7 can be improved.

[0159] The above technical solution introduces the first insulating component 24. The first insulator 241 can isolate and protect the first pole ear 212 and the second pole piece body 221 to reduce the risk of short circuit caused by overlapping of the first pole ear 212 and the second pole piece body 221; the second insulator 242 can isolate and protect the second pole ear 222 and the first pole piece body 211 to reduce the risk of short circuit caused by overlapping of the second pole ear 222 and the first pole piece body 211, which can effectively improve the reliability and product yield of the battery cell 7.

[0160] In some embodiments, the projection of the first insulator 241 along the first direction Y covers the projection of the second pole piece body 221 along the first direction Y. The first insulator 241 can completely cover the end of the second pole piece body 221 close to the first pole ear 212 along the first direction Y, thereby further improving the effect of the first insulator 241 isolating and protecting the first pole ear 212 and the second pole piece body 221.

[0161] In some embodiments, the projection of the second insulator 242 along the first direction Y covers the projection of the first pole piece body 211 along the first direction Y. The second insulator 242 can completely cover the end of the first pole piece body 211 close to the second pole ear 222 along the first direction Y, thereby further improving the effect of the second insulator 242 in isolating and protecting the second pole ear 222 and the first pole piece body 211.

[0162] In some embodiments, the first insulator 241 is connected to the first tab 212, and the second insulator 242 is connected to the second tab 222. In other words, the first insulator 241 is formed on the surface of the first tab 212 along the thickness direction X, and the second insulator 242 is formed on the surface of the second tab 222 along the thickness direction X.

[0163] Exemplarily, an insulating material may be coated or sprayed on the surface of the first pole ear 212 along the thickness direction X to form a first insulator 241, and an insulating material may be coated or sprayed on the surface of the second pole ear 222 along the thickness direction X to form a second insulator 242, and then the first pole piece 21 and the second pole piece 22 are assembled so that the first insulator 241 is arranged at one end of the second pole piece body 221 along the first direction Y close to the first pole ear 212, and the second insulator 242 is arranged at one end of the first pole piece body 211 along the first direction Y close to the second pole ear 222.

[0164] After the first pole piece 21 and the second pole piece 22 are assembled, a splicing structure can be formed between the first insulator 241 , the second insulator 242 , the first pole piece body 211 and the second pole piece body 221 , so that the electrode assembly 20 is more compact.

[0165] Furthermore, it is easy to understand that, in the above technical solution, before the electrode assembly 20 is subjected to a densification process such as compaction or hot pressing, the first insulator 241 is formed on the surface of the first pole ear 212 along the thickness direction X, and the second insulator 242 is formed on the surface of the second pole ear 222 along the thickness direction X. Furthermore, during the process of the electrode assembly 20 being subjected to a densification process such as compaction or hot pressing, the first insulator 241 can isolate and protect the first pole ear 212 and the second pole piece body 221 to reduce the risk of short circuit caused by the overlap of the first pole ear 212 and the second pole piece body 221, and the second insulator 242 can isolate and protect the second pole ear 222 and the first pole piece body 211 to reduce the risk of short circuit caused by the overlap of the second pole ear 222 and the first pole piece body 211.

[0166] As an example, the first insulator 241 may be connected to a side surface of the first pole tab 212 along the thickness direction X, and protrude from a side surface of the first pole piece body 211 along the thickness direction X.

[0167] As an example, the first insulator 241 may also be connected to the two opposite side surfaces of the first pole tab 212 along the thickness direction X, and protrude from the two opposite side surfaces of the first pole piece body 211 along the thickness direction X.

[0168] As an example, the second insulator 242 may be connected to a side surface of the second pole tab 222 along the thickness direction X, and protrude from a side surface of the second pole piece body 221 along the thickness direction X.

[0169] As an example, the second insulator 242 may also be connected to the two opposite side surfaces of the second pole tab 222 along the thickness direction X, and protrude from the two opposite side surfaces of the second pole piece body 221 along the thickness direction X.

[0170] It can be understood that the thickness of the pole piece is relatively thin. Compared with the end of the first pole piece 21 along the first direction Y, the surface of the first pole ear 212 along the thickness direction X has a relatively large setting space. The first insulator 241 is connected to the first pole ear 212, which helps to reduce the difficulty of setting the first insulator 241.

[0171] Compared with the end of the second pole piece 22 along the first direction Y, the surface of the second pole tab 222 along the thickness direction X has a relatively large installation space. The second insulator 242 is connected to the second pole tab 222 , which helps to reduce the difficulty of installing the second insulator 242 .

[0172] In this way, the above technical solution can not only reduce the difficulty of setting the first insulator 241 and the second insulator 242 , but also improve the structural compactness of the electrode assembly 20 , which helps to improve the energy density of the battery cell 7 .

[0173] In some embodiments, at least a portion of an end of the second pole piece body 221 facing away from the second pole tab 222 abuts against the first insulator 241 .

[0174] Exemplarily, one end of the second pole piece body 221 facing away from the second pole ear 222 may be partially in contact with the first insulator 241 , or may be completely in contact with the first insulator 241 .

[0175] The above technical solution enables the first insulator 241 to limit the displacement of the second pole piece 22 along the first direction Y to a certain extent, so as to improve the overall structural stability of the electrode assembly 20.

[0176] In some embodiments, at least a portion of an end of the first pole piece body 211 facing away from the first pole tab 212 abuts against the second insulator 242 .

[0177] Exemplarily, one end of the first pole piece body 211 facing away from the first pole ear 212 may be partially in contact with the first insulator 241 , or may be completely in contact with the first insulator 241 .

[0178] The above technical solution enables the second insulator 242 to limit the displacement of the first pole piece 21 along the first direction Y to a certain extent, so as to improve the overall structural stability of the electrode assembly 20.

[0179] In some embodiments, the first electrode body 211 includes a first current collector 2111, a first active material layer 2112 and a second active material layer 2113, the first active material layer 2112 and the second active material layer 2113 are respectively coated on the two side surfaces of the first current collector 2111 opposite to each other along the thickness direction X, and the first insulator 241 is connected to the side of the first electrode ear 212 close to the first active material layer 2112, and protrudes from the side surface of the first active material layer 2112 facing away from the first current collector 2111.

[0180] The second electrode body 221 includes a second current collector 2211, a third active material layer 2212 and a fourth active material layer 2213. The third active material layer 2212 and the fourth active material layer 2213 are respectively connected to the two side surfaces of the second current collector 2211 opposite to each other along the thickness direction X. The second insulator 242 is connected to the side of the second electrode ear 222 close to the third active material layer 2212, and protrudes from the side surface of the third active material layer 2212 facing away from the second current collector 2211.

[0181] The first active material layer 2112 and the third active material layer 2212 are disposed opposite to each other, and the second active material layer 2113 and the fourth active material layer 2213 are disposed opposite to each other.

[0182] Exemplarily, the first insulator 241 is located on a side of the first active material layer 2112 close to the first pole ear 212 along the first direction Y. After the first pole piece 21 and the second pole piece 22 are assembled to form the electrode assembly 20, the second pole piece body 221 is located on a side of the first insulator 241 close to the first pole piece body 211 along the first direction Y. The second insulator 242 is located on a side of the third active material layer 2212 close to the second pole ear 222 along the first direction Y. After the first pole piece 21 and the second pole piece 22 are assembled to form the electrode assembly 20, the first pole piece body 211 is located on a side of the second insulator 242 close to the second pole piece body 221 along the first direction Y.

[0183] The first active material layer 2112 and the third active material layer 2212 are arranged opposite to each other. It can be understood that after the first electrode sheet 21 and the second electrode sheet 22 are assembled to form the electrode assembly 20, the first active material layer 2112 and the third active material layer 2212 are opposite to each other along the thickness direction X.

[0184] The second active material layer 2113 and the fourth active material layer 2213 are arranged opposite to each other. It can be understood that after the first electrode sheet 21 and the second electrode sheet 22 are assembled to form the electrode assembly 20, the second active material layer 2113 and the fourth active material layer 2213 are opposite to each other along the thickness direction X.

[0185] The second pole piece body 221 is located on a side of the first insulator 241 along the first direction Y close to the first pole piece body 211 , and there are multiple specific configuration methods.

[0186] As an example, the third active material layer 2212 may be located on a side of the first insulator 241 close to the first electrode body 211 along the first direction Y. In other words, the projection of the first insulator 241 along the first direction Y overlaps with the projection of the third active material layer 2212 along the first direction Y.

[0187] Furthermore, one end of the third active material layer 2212 facing away from the second electrode tab 222 abuts against the first insulator 241 .

[0188] As an example, the third active material layer 2212 and the second current collector 2211 may be both located on a side of the first insulator 241 close to the first pole piece body 211 along the first direction Y. In other words, the projection of the first insulator 241 along the first direction Y overlaps with the projection of the third active material layer 2212 along the first direction Y, and the projection of the first insulator 241 along the first direction Y overlaps with the projection of the second current collector 2211 along the first direction Y.

[0189] Furthermore, one end of the third active material layer 2212 facing away from the second electrode tab 222 and one end of the second current collector 2211 facing away from the second electrode tab 222 both abut against the first insulator 241 .

[0190] As an example, the third active material layer 2212, the second current collector 2211, and the fourth active material layer 2213 may all be located on the side of the first insulator 241 close to the first electrode body 211 along the first direction Y. In other words, the projection of the first insulator 241 along the first direction Y overlaps with the projection of the third active material layer 2212 along the first direction Y, the projection of the first insulator 241 along the first direction Y overlaps with the projection of the second current collector 2211 along the first direction Y, and the projection of the first insulator 241 along the first direction Y overlaps with the projection of the fourth active material layer 2213 along the first direction Y.

[0191] Furthermore, one end of the third active material layer 2212 facing away from the second electrode tab 222 , one end of the second current collector 2211 facing away from the second electrode tab 222 , and one end of the fourth active material layer 2213 facing away from the second electrode tab 222 all abut against the first insulator 241 .

[0192] The first pole piece body 211 is located on a side of the second insulator 242 along the first direction Y close to the second pole piece body 221 , and there are multiple specific configurations.

[0193] As an example, the first active material layer 2112 may be located on a side of the second insulator 242 close to the second electrode body 221 along the first direction Y. In other words, the projection of the second insulator 242 along the first direction Y overlaps with the projection of the first active material layer 2112 along the first direction Y.

[0194] Furthermore, one end of the first active material layer 2112 facing away from the first electrode tab 212 abuts against the second insulator 242 .

[0195] As an example, the first active material layer 2112 and the first current collector 2111 may be both located on the side of the second insulator 242 close to the second electrode body 221 along the first direction Y. In other words, the projection of the second insulator 242 along the first direction Y overlaps with the projection of the first active material layer 2112 along the first direction Y, and the projection of the second insulator 242 along the first direction Y overlaps with the projection of the first current collector 2111 along the first direction Y.

[0196] Furthermore, one end of the first active material layer 2112 facing away from the first electrode tab 212 and one end of the first current collector 2111 facing away from the first electrode tab 212 both abut against the second insulator 242 .

[0197] As an example, the first active material layer 2112, the first current collector 2111, and the second active material layer 2113 may all be located on the side of the second insulator 242 close to the second electrode body 221 along the first direction Y. In other words, the projection of the second insulator 242 along the first direction Y overlaps with the projection of the first active material layer 2112 along the first direction Y, the projection of the second insulator 242 along the first direction Y overlaps with the projection of the first current collector 2111 along the first direction Y, and the projection of the second insulator 242 along the first direction Y overlaps with the projection of the second active material layer 2113 along the first direction Y.

[0198] Furthermore, one end of the first active material layer 2112 facing away from the first electrode tab 212 , one end of the first current collector 2111 facing away from the first electrode tab 212 , and one end of the second active material layer 2113 facing away from the first electrode tab 212 all abut against the second insulator 242 .

[0199] The above technical solution sets the first insulator 241 only on one side of the first pole ear 212 along the thickness direction X, and sets the second insulator 242 only on one side of the second pole ear 222 along the thickness direction X, so that the first pole piece 21 and the second pole piece 22 form a spliced ​​assembly structure, which helps to simplify the preparation process of the electrode assembly 20 and reduce costs.

[0200] In some embodiments, the projection of the second active material layer 2113 along the thickness direction X partially overlaps with the projection of the first insulator 241 along the thickness direction X. This allows the second active material layer 2113 to fill the gap between the first insulator 241 and the first electrode tab 212 to a certain extent, thereby improving the overall structural compactness and stability of the electrode assembly 20.

[0201] In some embodiments, the projection of the fourth active material layer 2213 along the thickness direction X partially overlaps with the projection of the second insulator 242 along the thickness direction X. This allows the fourth active material layer 2213 to fill the gap between the second insulator 242 and the second electrode tab 222 to a certain extent, thereby improving the overall structural compactness and stability of the electrode assembly 20.

[0202] In some embodiments, the projection of the second active material layer 2113 along the thickness direction X does not overlap with the projection of the first insulator 241 along the thickness direction X. This allows the first active material layer 2112 and the second active material layer 2113 to be provided with the same coating width, which helps to reduce the difficulty of preparing the first electrode sheet 21 .

[0203] In some embodiments, the projection of the fourth active material layer 2213 along the thickness direction X does not overlap with the projection of the second insulator 242 along the thickness direction X. This allows the third active material layer 2212 and the fourth active material layer 2213 to be provided with the same coating width, which helps to reduce the difficulty of preparing the second electrode sheet 22 .

[0204] In some embodiments, a first dimension L1 of the first active material layer 2112 along the first direction Y, a second dimension L2 of the second active material layer 2113 along the first direction Y, and a third dimension L3 of the first insulator 241 along the first direction Y satisfy the relationship: L2≤L1+L3.

[0205] Exemplarily, the first dimension L1 of the first active material layer 2112 along the first direction Y can be understood as the coating width of the first active material layer 2112, the second dimension L2 of the second active material layer 2113 along the first direction Y can be understood as the coating width of the second active material layer 2113, and the third dimension L3 of the first insulator 241 along the first direction Y can be understood as the coating width of the first insulator 241. The width refers to the length relative to the pole piece. For example, in a winding structure, the dimension of the pole piece along the winding direction V is the length.

[0206] It can be understood that the first pole tab 212 is a portion of the first current collector 2111 that is not provided with an active material layer. The larger the size of the active material layer along the first direction Y, the smaller the effective size of the first pole tab 212. The effective size of the first pole tab 212 will affect the subsequent processing and assembly difficulty of the electrode assembly 20, such as the flattening treatment of the first pole tab 212, the connection between the first pole tab 212 and the electrode terminal, etc. The smaller the effective size of the first pole tab 212, the greater the subsequent processing and assembly difficulty of the electrode assembly 20.

[0207] In this way, the above technical solution can, to a certain extent, avoid the second active material layer 2113 being too large in size along the first direction Y, which would cause the effective size of the first electrode tab 212 to be too small, thereby reducing the difficulty of processing and assembling the electrode assembly 20 .

[0208] In some embodiments, the first size L1 satisfies the relationship: 20 mm ≤ L1 ≤ 2000 mm, and the third size L3 satisfies the relationship: 15 um ≤ L3 ≤ 2000 um.

[0209] As an example, the first size L1 may be, but is not limited to, 20mm, 100mm, 200mm, 500mm, 1000mm, 1500mm, 2000mm, etc. The third size L3 may be, but is not limited to, 15um, 50um, 100um, 500um, 1000um, 1500um, 2000um, etc.

[0210] It can be understood that the larger the first dimension L1 is, the greater the energy density of the battery cell 7 is, and at the same time, the smaller the setting range of the first insulator 241 is; the larger the third dimension L3 is, the better the insulating spacing effect of the first insulator 241 is, and the smaller the setting range of the first active material layer 2112 is.

[0211] The above technical solution can reduce the influence of the first insulator 241 on the energy density of the battery cell 7 while ensuring that the first insulator 241 has a reliable insulating spacing effect by setting the first size L1 and the third size L3 within the above range.

[0212] In some embodiments, the first dimension L1 satisfies the relationship: 40 mm ≤ L1 ≤ 1000 mm, and the third dimension L3 satisfies the relationship: 30 um ≤ L3 ≤ 1000 um. This can further improve the balance between the reliability and energy density of the battery cell 7 .

[0213] As an example, the first size L1 may be, but is not limited to, 40 mm, 300 mm, 500 mm, 700 mm, 800 mm, 900 mm, 1000 mm, etc. The third size L3 may be, but is not limited to, 30 um, 40 um, 200 um, 600 um, 800 um, 1000 um, etc.

[0214] In some embodiments, a fourth size L4 of the third active material layer 2212 along the first direction Y, a fifth size L5 of the fourth active material layer 2213 along the first direction Y, and a sixth size L6 of the second insulator 242 along the first direction Y satisfy the relationship: L5≤L4+L6.

[0215] Exemplarily, the fourth dimension L4 of the third active material layer 2212 along the first direction Y can be understood as the coating width of the third active material layer 2212, the fifth dimension L5 of the fourth active material layer 2213 along the first direction Y can be understood as the coating width of the fourth active material layer 2213, and the sixth dimension L6 of the second insulator 242 along the first direction Y can be understood as the coating width of the second insulator 242.

[0216] It can be understood that the second pole tab 222 is a portion of the second current collector 2211 that is not provided with an active material layer. The larger the size of the active material layer along the first direction Y, the smaller the effective size of the second pole tab 222. The effective size of the second pole tab 222 will affect the subsequent processing and assembly difficulty of the electrode assembly 20, such as the flattening treatment of the second pole tab 222, the connection between the second pole tab 222 and the electrode terminal, etc. The smaller the effective size of the second pole tab 222, the greater the subsequent processing and assembly difficulty of the electrode assembly 20.

[0217] In this way, the above technical solution can, to a certain extent, avoid the fourth active material layer 2213 being too large in size along the first direction Y, which would cause the effective size of the second electrode tab 222 to be too small, thereby reducing the difficulty of processing and assembling the electrode assembly 20 .

[0218] In some embodiments, the fourth dimension L4 satisfies the relationship: 20 mm ≤ L4 ≤ 2000 mm, and the sixth dimension L6 satisfies the relationship: 15 um ≤ L6 ≤ 2000 um.

[0219] As an example, the fourth size L4 may be, but is not limited to, 20mm, 100mm, 200mm, 500mm, 1000mm, 1500mm, 2000mm, etc. The sixth size L6 may be, but is not limited to, 15um, 50um, 100um, 500um, 1000um, 1500um, 2000um, etc.

[0220] It can be understood that the larger the fourth dimension L4 is, the greater the energy density of the battery cell 7 is, and at the same time, the smaller the setting range of the second insulator 242 is; the larger the sixth dimension L6 is, the better the insulating spacing effect of the second insulator 242 is, and the smaller the setting range of the third active material layer 2212 is.

[0221] The above technical solution can reduce the influence of the second insulator 242 on the energy density of the battery cell 7 while ensuring that the second insulator 242 has a reliable insulating spacing effect by setting the fourth dimension L4 and the sixth dimension L6 within the above range.

[0222] In some embodiments, the fourth dimension L4 satisfies the relationship: 40 mm ≤ L4 ≤ 1000 mm, and the sixth dimension L6 satisfies the relationship: 30 um ≤ L6 ≤ 1000 um, which can further improve the balance between the reliability and energy density of the battery cell 7 .

[0223] As an example, the fourth size L4 may be, but is not limited to, 40 mm, 300 mm, 500 mm, 700 mm, 800 mm, 900 mm, 1000 mm, etc. The sixth size L6 may be, but is not limited to, 30 um, 40 um, 200 um, 600 um, 800 um, 1000 um, etc.

[0224] In some embodiments, a first dimension L1 of the first active material layer 2112 along the first direction Y and a fourth dimension L4 of the third active material layer 2212 along the first direction Y satisfy the relationship: -2 mm ≤ L1 - L4 ≤ 2 mm.

[0225] As an example, L1-L4 can be but is not limited to -2mm, -1mm, -0.5mm, 0, 0.5mm, 1mm, 2mm, etc.

[0226] It can be understood that the greater the difference between the first dimension L1 of the first active material layer 2112 along the first direction Y and the fourth dimension L4 of the third active material layer 2212 along the first direction Y, the larger the gap inside the electrode assembly 20 will be after the first pole piece 21 and the second pole piece 22 are assembled to form the electrode assembly 20, and the greater the risk of deformation or collapse of the electrode assembly 20 during the densification process such as compaction or hot pressing of the electrode assembly 20, or when the battery cell 7 is vibrated or impacted during use.

[0227] In this way, the above technical solution can reduce the gap inside the electrode assembly 20 and improve the reliability of the electrode assembly 20 by setting the difference between the first size L1 and the fourth size L4 within the above range.

[0228] In some embodiments, the first size L1 and the fourth size L4 satisfy the relationship: −0.5 mm ≤ L1 − L4 ≤ 0.5 mm. The gap inside the electrode assembly 20 can be further reduced to further improve the reliability of the electrode assembly 20 .

[0229] As an example, L1-L4 can be but is not limited to -0.5mm, -0.4mm, -0.3mm, -0.2mm, -0.1mm, 0, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, etc.

[0230] In some embodiments, a surface of the first insulator 241 away from the first current collector 2111 along the thickness direction X is flush with a surface of the fourth active material layer 2213 away from the second current collector 2211 along the thickness direction X. This can effectively improve the structural consistency and compactness of the electrode assembly 20, and help further improve the reliability of the electrode assembly 20.

[0231] In some embodiments, the surface of the second insulator 242 away from the second current collector 2211 along the thickness direction X is flush with the surface of the first active material layer 2112 away from the first current collector 2111 along the thickness direction X. This can effectively improve the structural consistency and compactness of the electrode assembly 20, and help further improve the reliability of the electrode assembly 20.

[0232] In some embodiments, the solid electrolyte 23 includes a first electrolyte layer 231 and a second electrolyte layer 232 , and the first electrolyte layer 231 and the second electrolyte layer 232 are respectively coated on two opposite sides of the second electrode body 221 along the thickness direction X.

[0233] Illustratively, during the preparation of the second electrode sheet 22, the third active material layer 2212 and the fourth active material layer 2213 are first coated on the two side surfaces of the second current collector 2211 opposite to each other along the thickness direction X, and then the solid electrolyte 23 is coated on the side surface of the third active material layer 2212 facing away from the second current collector 2211 to form a first electrolyte layer 231; the solid electrolyte 23 is coated on the side surface of the fourth active material layer 2213 facing away from the second current collector 2211 to form a second electrolyte layer 232.

[0234] By directly coating the solid electrolyte 23 on the second electrode sheet body 221 , the preparation process of the electrode assembly 20 can be simplified, which helps to reduce costs.

[0235] In some embodiments, the first pole piece 21 and the second pole piece 22 are wound along a winding direction V, and the first pole tab 212 and the second pole tab 222 are arranged opposite to each other along the first direction Y.

[0236] The first pole lug 212 is wound along the winding direction V and includes multiple turns of the first pole lug layer. The second pole lug 222 is wound along the winding direction V and includes multiple turns of the second pole lug layer. The first insulator 241 is arranged between two adjacent turns of the first pole lug layer. The second insulator 242 is arranged between two adjacent turns of the second pole lug layer.

[0237] Exemplarily, the electrode assembly 20 formed by winding the first pole piece 21 and the second pole piece 22 along the winding direction V may be cylindrical. The first pole piece body 211 and the second pole piece body 221 are wound to form the electrode body, and the first pole ear 212 and the second pole ear 222 are arranged opposite to each other along the first direction Y, which means that the first pole ear 212 and the second pole ear 222 are respectively led out from opposite ends of the electrode body along the first direction Y.

[0238] The two ends of the first pole tab 212 along the winding direction V are an inner end and an outer end respectively. In this embodiment, the first pole tab layer is divided based on the inner end of the first pole tab 212. The winding direction V is perpendicular to the winding axis.

[0239] Specifically, the inner end of the first pole lug 212 is the head end of the first circle of the first pole lug layer, the tail end of the first circle of the first pole lug layer is aligned with the head end of the first circle of the first pole lug layer in the radial direction of the first pole lug 212, and the first circle of the first pole lug layer surrounds the winding axis once. Correspondingly, the tail end of the first circle of the first pole lug layer is the head end of the second circle of the first pole lug layer, and so on, multiple circles of the first pole lug layers are connected end to end along the winding direction V. When dividing the first pole lug layer, the head end of each circle of the first pole lug layer is aligned with the inner end of the first pole lug 212 in the radial direction of the first pole lug 212. Among them, the radial direction of the first pole lug 212 is perpendicular to the winding axis and passes through the winding axis.

[0240] Exemplarily, the inner end and the outer end of the first pole tab 212 are aligned in the radial direction of the first pole tab 212 , so that each turn of the pole tab layer surrounds the winding axis once.

[0241] Of course, alternatively, there is a portion at the tail of the first pole ear 212, which surrounds the winding axis less than one circle, for example, the portion can surround 1 / 3, 1 / 2, 2 / 3 or 3 / 4 of the winding axis.

[0242] After winding, the first tab 212 is generally cylindrical, with a gap between two adjacent first tab layers. The first insulator 241 is disposed between two adjacent first tab layers, which can be understood as the first insulator 241 being disposed in the gap between two adjacent first tab layers.

[0243] As an example, the first insulator 241 is connected between two adjacent turns of the first tab layers along a direction perpendicular to the winding axis.

[0244] The two ends of the second pole tab 222 along the winding direction V are an inner end and an outer end respectively. In this embodiment, the second pole tab layer is divided based on the inner end of the second pole tab 222. The winding direction V is perpendicular to the winding axis.

[0245] Specifically, the inner end of the second pole lug 222 is the head end of the first circle of the second pole lug layer, the tail end of the first circle of the second pole lug layer is aligned with the head end of the first circle of the second pole lug layer in the radial direction of the second pole lug 222, and the first circle of the second pole lug layer surrounds the winding axis once. Correspondingly, the tail end of the first circle of the second pole lug layer is the head end of the second circle of the second pole lug layer, and so on, multiple circles of the second pole lug layers are connected end to end along the winding direction V. When dividing the second pole lug layer, the head end of each circle of the second pole lug layer is aligned with the inner end of the second pole lug 222 in the radial direction of the second pole lug 222. Among them, the radial direction of the second pole lug 222 is perpendicular to the winding axis and passes through the winding axis.

[0246] Exemplarily, the inner end and the outer end of the second pole tab 222 are aligned in the radial direction of the second pole tab 222 , so that each turn of the pole tab layer surrounds the winding axis once.

[0247] Of course, alternatively, there is a portion at the tail of the second pole ear 222, which surrounds the winding axis less than one circle, for example, the portion can surround 1 / 3, 1 / 2, 2 / 3 or 3 / 4 of the winding axis.

[0248] After winding, the second tab 222 is generally cylindrical, with a gap between two adjacent second tab layers. The first insulator 241 is disposed between two adjacent second tab layers, which can be understood as the first insulator 241 being disposed in the gap between two adjacent second tab layers.

[0249] As an example, the first insulator 241 is connected between two adjacent turns of the second tab layers along a direction perpendicular to the winding axis.

[0250] It can be understood that, compared with the electrode assembly 20 with a stacked structure, the electrode assembly 20 with a wound structure has a larger area of ​​the pole ear. Therefore, during the densification process such as compaction or hot pressing of the electrode assembly 20, or when the battery cell 7 is vibrated or impacted during use, the pole ears of the electrode assembly 20 with a wound structure are more likely to deform or collapse, and the risk of short circuit is greater.

[0251] In this way, the above technical solution can greatly reduce the risk of short circuit of the electrode assembly 20 with a winding structure, improve the shortcomings of the solid-state battery cell 7 with the electrode assembly 20 with a winding structure, and effectively improve the economic benefits of the solid-state battery cell 7 with the electrode assembly 20 with a winding structure.

[0252] Figure 8 A cross-sectional schematic diagram of an electrode assembly of a battery cell provided in some embodiments of the present application.

[0253] Continue to refer Figure 8 In some embodiments, the battery cell 7 further includes a supporting component 30 , and the first pole piece 21 and the second pole piece 22 are wound around the supporting component 30 .

[0254] The support component 30 is used to support the first pole piece 21 and the second pole piece 22 to reduce the risk of the first pole piece 21 and the second pole piece 22 being deformed or collapsed inwardly under the action of external force, thereby improving the reliability of the battery cell 7 .

[0255] As an example, the supporting component 30 is made of insulating material, wherein the insulating material includes but is not limited to various organic insulating materials such as epoxy acrylate, polyurethane acrylate, resin glue, rubber, etc., and also includes but is not limited to various inorganic insulating materials such as mica, asbestos, etc., as well as insulating materials formed by mixing the above-mentioned organic insulating materials and the above-mentioned inorganic insulating materials.

[0256] As an example, the support member 30 is a cylindrical structure.

[0257] In some embodiments, a surface of the first insulator 241 away from the second pole piece body 221 along the first direction Y is flush with an end surface of the support component 30 close to the first pole ear 212 along the first direction Y. This can improve the structural consistency of the electrode assembly 20 and reduce the difficulty of processing or assembling the electrode assembly 20.

[0258] In some embodiments, a side surface of the second insulator 242 away from the first pole piece body 211 along the first direction Y is flush with a side end surface of the support component 30 close to the second pole ear 222 along the first direction Y. This can improve the structural consistency of the electrode assembly 20 and reduce the difficulty of processing or assembling the electrode assembly 20.

[0259] Fig. 9 A schematic diagram of the winding structure of a first pole piece and a second pole piece of a battery cell provided in some embodiments of the present application.

[0260] Continue to refer Fig. 9 In some embodiments, in the winding direction V, both ends of the second pole piece 22 extend beyond both ends of the first pole piece 21. The electrode assembly 20 further includes a second insulating component 40, which is connected to both ends of the first pole piece 21 along the winding direction V and is used to insulate both ends of the first pole piece 21 along the winding direction V from the second pole piece 22.

[0261] In this embodiment, the first electrode sheet 21 is a positive electrode sheet, and the second electrode sheet 22 is a negative electrode sheet.

[0262] Exemplarily, the two ends of the first pole piece 21 along the winding direction V are the head end and the tail end, respectively. The second insulating component 40 is connected to the head end of the first pole piece 21 along the winding direction V. In the direction perpendicular to the winding axis, even if the second pole pieces 22 located on both sides of the head end of the first pole piece 21 along the winding direction V are deformed or moved in the direction close to the head end of the first pole piece 21 along the winding direction V under the action of mechanical stress, the second insulating component 40 can provide insulating support for the second pole piece 22, thereby reducing the risk of the head end of the first pole piece 21 along the winding direction V overlapping the second pole piece 22.

[0263] The second insulating component 40 is connected to the tail end of the first pole piece 21 along the winding direction V. In the direction perpendicular to the winding axis, even if the second pole piece 22 located on both sides of the tail end of the first pole piece 21 along the winding direction V is deformed or moved in the direction close to the tail end of the first pole piece 21 along the winding direction V under the action of mechanical stress, the second insulating component 40 can provide insulating support for the second pole piece 22, thereby reducing the risk of overlap between the tail end of the first pole piece 21 along the winding direction V and the second pole piece 22.

[0264] As an example, the second insulating component 40 may be an insulating tape or an insulating glue.

[0265] The above technical solution can further reduce the risk of overlapping and short-circuiting the first pole piece 21 and the second pole piece 22 by introducing the second insulating component 40 , so as to further improve the reliability of the battery cell 7 .

[0266] According to some embodiments of the present application, the present application further provides a battery device, comprising a battery cell 7 of any of the above solutions.

[0267] According to some embodiments of the present application, the present application further provides an electrical device, comprising a battery cell 7 or a battery device according to any of the above schemes, wherein the battery cell 7 or the battery device is used to store or provide electrical energy.

[0268] If not otherwise specified, all implementations and optional implementations of the present application can be combined with each other to form a new technical solution. All technical features and optional technical features of the present application can be combined with each other to form a new technical solution.

[0269] In order to better understand the battery cell 7 provided in the embodiment of the present application, based on the same inventive concept, an embodiment of the above-mentioned battery cell 7 in actual application is provided here for illustration.

[0270] The embodiment of the present application provides a battery cell 7, which includes a shell 10 and an electrode assembly 20. The electrode assembly 20 is accommodated in the shell 10. The electrode assembly 20 includes pole pieces, a solid electrolyte 23 and a first insulating component 24. The pole pieces include a first pole piece 21 and a second pole piece 22. The first pole piece 21 and the second pole piece 22 are staggered along the thickness direction X of the pole piece and have opposite polarities. The solid electrolyte 23 is arranged between the first pole piece 21 and the second pole piece 22.

[0271] The first pole piece 21 includes a first pole piece body 211 and a first pole ear 212, the first pole ear 212 is connected to one side of the first pole piece body 211 along the first direction Y, and the second pole piece 22 includes a second pole piece body 221 and a second pole ear 222, the second pole ear 222 is connected to one side of the second pole piece body 221 along the first direction Y, and the first direction Y is perpendicular to the thickness direction X of the pole piece. The first pole piece 21 and the second pole piece 22 are wound along the winding direction V. The first pole ear 212 is connected to one side of the first pole piece body 211 along the first direction Y, the second pole ear 222 is connected to one side of the second pole piece body 221 along the first direction Y, and the first pole ear 212 and the second pole ear 222 are arranged opposite to each other along the first direction Y. The first pole ear 212 is wound along the winding direction V and includes a plurality of turns of the first pole ear layer, and the second pole ear 222 is wound along the winding direction V and includes a plurality of turns of the second pole ear layer.

[0272] The first insulating component 24 includes a first insulator 241 and a second insulator 242. The first insulator 241 is disposed at one end of the second pole piece body 221 close to the first pole ear 212 along the first direction Y and is located between two adjacent circles of the first pole ear 212 layers, and is used to insulate the first pole ear 212 from the second pole piece body 221. The second insulator 242 is disposed at one end of the first pole piece body 211 close to the second pole ear 222 along the first direction Y and is located between two adjacent circles of the second pole ear 222 layers, and is used to insulate the second pole ear 222 from the first pole piece body 211. One end of the second pole piece body 221 facing away from the second pole ear 222 abuts against one side of the first insulator 241 close to the first pole piece body 211 along the first direction Y. One end of the first pole piece body 211 facing away from the first pole ear 212 abuts against one side of the second insulator 242 close to the second pole piece body 221 along the first direction Y.

[0273] The above technical solution introduces the first insulating component 24. The first insulator 241 can isolate and protect the first pole ear 212 and the second pole piece body 221 to reduce the risk of short circuit caused by overlapping of the first pole ear 212 and the second pole piece body 221; the second insulator 242 can isolate and protect the second pole ear 222 and the first pole piece body 211 to reduce the risk of short circuit caused by overlapping of the second pole ear 222 and the first pole piece body 211, which can effectively improve the reliability and product yield of the battery cell 7.

[0274] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0275] 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. A battery cell, characterized in that: include: shell; An electrode assembly is contained in the housing, the electrode assembly comprises a pole piece, a solid electrolyte and a first insulating component, the pole piece comprises a first pole piece and a second pole piece, the first pole piece and the second pole piece are staggered along the thickness direction of the pole piece and have opposite polarities, the solid electrolyte is arranged between the first pole piece and the second pole piece, The first pole piece includes a first pole piece body and a first pole ear, wherein the first pole ear is connected to one side of the first pole piece body along a first direction, and the second pole piece includes a second pole piece body and a second pole ear, wherein the second pole ear is connected to one side of the second pole piece body along the first direction, wherein the first direction is perpendicular to the thickness direction of the pole piece. The first insulating component includes a first insulator and a second insulator, the first insulator is arranged at one end of the second pole piece body close to the first pole ear along the first direction, and is used to insulate the first pole ear from the second pole piece body, the second insulator is arranged at one end of the first pole piece body close to the second pole ear along the first direction, and is used to insulate the second pole ear from the first pole piece body; The first insulator is formed on the surface of the first pole tab along the thickness direction of the pole piece, and the second insulator is formed on the surface of the second pole tab along the thickness direction of the pole piece.

2. The battery cell according to claim 1, characterized in that: The projection of the first insulator along the first direction covers the projection of the second pole piece body along the first direction; and / or, The projection of the second insulator along the first direction covers the projection of the first pole piece body along the first direction.

3. The battery cell according to claim 1, characterized in that: The first pole piece body comprises a first current collector, a first active material layer and a second active material layer, the first active material layer and the second active material layer are respectively coated on two opposite surfaces of the first current collector along the thickness direction, the first insulator is connected to a side of the first pole tab close to the first active material layer, and protrudes from a side of the first active material layer facing away from the first current collector; The second pole piece body comprises a second current collector, a third active material layer and a fourth active material layer, wherein the third active material layer and the fourth active material layer are respectively connected to two opposite surfaces of the second current collector along the thickness direction, and the second insulator is connected to a side of the second pole tab close to the third active material layer and protrudes from a side surface of the third active material layer facing away from the second current collector; The first active material layer and the third active material layer are arranged opposite to each other, and the second active material layer and the fourth active material layer are arranged opposite to each other.

4. The battery cell according to claim 3, characterized in that: The projection of the second active material layer along the thickness direction partially overlaps with the projection of the first insulator along the thickness direction; and / or, A projection of the fourth active material layer along the thickness direction partially overlaps a projection of the second insulator along the thickness direction.

5. The battery cell according to claim 3, characterized in that: A first size L1 of the first active material layer along the first direction, a second size L2 of the second active material layer along the first direction, and a third size L3 of the first insulator along the first direction satisfy the relationship: L2≤L1+L3.

6. The battery cell according to claim 5, characterized in that: The first size L1 satisfies the relationship: 20mm≤L1≤2000mm, and the third size L3 satisfies the relationship: 15um≤L3≤2000um.

7. The battery cell according to claim 6, characterized in that: The first size L1 satisfies the relationship: 40mm≤L1≤1000mm, and the third size L3 satisfies the relationship: 30um≤L3≤1000um.

8. The battery cell according to claim 3, characterized in that: A fourth size L4 of the third active material layer along the first direction, a fifth size L5 of the fourth active material layer along the first direction, and a sixth size L6 of the second insulator along the first direction satisfy the relationship: L5≤L4+L6.

9. The battery cell according to claim 8, characterized in that: The fourth dimension L4 satisfies the relationship: 20mm≤L4≤2000mm, and the sixth dimension L6 satisfies the relationship: 15um≤L6≤2000um.

10. The battery cell according to claim 9, characterized in that: The fourth dimension L4 satisfies the relationship: 40mm≤L4≤1000mm, and the sixth dimension L6 satisfies the relationship: 30um≤L6≤1000um.

11. The battery cell according to claim 3, characterized in that: A first dimension L1 of the first active material layer along the first direction and a fourth dimension L4 of the third active material layer along the first direction satisfy the relationship: -2 mm ≤ L1 - L4 ≤ 2 mm.

12. The battery cell according to claim 11, characterized in that: The first size L1 and the fourth size L4 satisfy the relationship: -0.5 mm ≤ L1 - L4 ≤ 0.5 mm.

13. The battery cell according to claim 3, characterized in that: A surface of the first insulator along the thickness direction away from the first current collector is flush with a surface of the fourth active material layer along the thickness direction away from the second current collector; and / or, A surface of the second insulator at one side away from the second current collector along the thickness direction is flush with a surface of the first active material layer at one side away from the first current collector along the thickness direction.

14. The battery cell according to claim 1, characterized in that: The solid electrolyte comprises a first electrolyte layer and a second electrolyte layer, wherein the first electrolyte layer and the second electrolyte layer are respectively coated on two opposite side surfaces of the second pole piece body along the thickness direction.

15. The battery cell according to claim 1, characterized in that: The first pole piece and the second pole piece are wound along a winding direction, and the first pole lug and the second pole lug are arranged opposite to each other along the first direction; The first pole tab is wound along the winding direction and includes multiple turns of the first pole tab layer, the second pole tab is wound along the winding direction and includes multiple turns of the second pole tab layer, the first insulator is arranged between two adjacent turns of the first pole tab layer, and the second insulator is arranged between two adjacent turns of the second pole tab layer.

16. The battery cell according to claim 15, characterized in that: The battery cell further includes a supporting component, and the first pole sheet and the second pole sheet are wound around the supporting component.

17. The battery cell according to claim 16, characterized in that: A surface of one side of the first insulator away from the second pole piece body along the first direction is flush with an end surface of one side of the support component close to the first pole ear along the first direction; and / or, A surface of the second insulator on one side away from the first pole piece body along the first direction is flush with an end surface of the support component on one side close to the second pole ear along the first direction.

18. The battery cell according to claim 15, characterized in that: In the winding direction, both ends of the second pole piece extend beyond both ends of the first pole piece; The electrode assembly further includes a second insulating component, which is connected to both ends of the first pole piece along the winding direction and is used to insulate the first pole piece from the second pole piece.

19. A battery device, characterized in that: The invention comprises a plurality of battery cells according to any one of claims 1 to 18.

20. An electrical device, characterized in that: The invention comprises a battery cell according to any one of claims 1 to 18 or a battery device according to claim 19, wherein the battery cell or the battery device is used for storing or providing electrical energy.

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