Battery pole piece, coating equipment and battery monomer

Abstract

The utility model relates to the technical field of new energy, in particular to a battery pole piece, coating equipment and a battery monomer, the battery pole piece comprises a pole piece main body, and active material layers are respectively arranged on two surfaces of the pole piece main body; the battery pole piece further comprises an identification layer; the identification layers are arranged on the two surfaces, and the shapes or positions of the coatings on the two surfaces are different. In this way, the two asymmetrically coated faces of the battery pole piece can be conveniently distinguished.

Description

[0001] This application is a divisional application of the utility model patent application with the application number 202290000337.0, the application date of December 29, 2022, and the invention name of "Battery Electrode Sheet, Coating Method, Coating Equipment and Battery Cell". Technical Field

[0002] This application relates to the field of new energy technologies, and in particular, to a battery electrode sheet, a coating method, coating equipment and a battery cell. Background Art

[0003] Power batteries work through the charge and discharge of the internal battery cell components. The battery cell components include electrode sheets and separators arranged at intervals. Active materials need to be coated on both sides of the electrode sheets to enable the battery cell components to have the charge and discharge function. With the rapid development of new energy, more and higher requirements are put forward for the performance of power batteries. To meet such requirements, the application of the asymmetric coating method on both sides of the electrode sheets in the battery cell components is becoming more and more widespread.

[0004] Since it is impossible to accurately identify both sides by the naked eye or machine after the asymmetric coating on both sides of the electrode sheet, the situation of incorrect identification of the battery electrode sheet will occur. Utility Model Content

[0005] In view of the above problems, this application provides a battery electrode sheet, a coating method, coating equipment and a battery cell, so as to facilitate the distinction between the two sides of the asymmetric coating of the battery electrode sheet.

[0006] According to one aspect of this application, a battery electrode sheet is provided. The battery electrode sheet includes a main electrode sheet body, and active material layers are respectively arranged on two surfaces of the main electrode sheet body; the battery electrode sheet further includes an identification layer; the identification layer is arranged on at least one surface and makes the shapes or positions of the coatings on the two surfaces different.

[0007] By arranging an identification layer on at least one surface of the main electrode sheet body and making the shapes or positions of the coatings on the two surfaces different, the two surfaces of the main electrode sheet body can be accurately identified and distinguished by the naked eye or machine, ensuring that the battery electrode sheet can be accurately positioned and assembled in production subsequently.

[0008] In some exemplary embodiments, the identification layer is arranged on only one surface. By arranging the active material layer and the identification layer on one of the surfaces of the main electrode sheet body and only arranging the active material layer on the other surface, the distinction and identification of the two sides of the battery electrode sheet are realized.

[0009] In some exemplary embodiments, identification layers are respectively arranged on the two surfaces, and the shapes or positions of the identification layers on the two surfaces are different. By setting the shapes or positions of the identification layers on the two surfaces of the main electrode sheet body to be different, the distinction and identification of the two sides of the battery electrode sheet are realized.

[0010] In some exemplary embodiments, on a surface provided with an identification layer, the identification layer and the active material layer extend along a first direction and are spaced apart along a second direction. Both the first direction and the second direction are located on the surface and are perpendicular to each other. By arranging the identification layer and the active material layer to extend along the first direction, the neatness of the appearance of the battery electrode sheet is ensured, and it is convenient for coating the identification layer and the active material layer. By arranging the identification layer and the active material layer to be spaced apart along the second direction, it is possible to prevent the identification layer from contacting the active material layer, making the identification layer difficult to identify, thus causing difficulty in distinguishing between the two sides of the battery electrode sheet.

[0011] In some exemplary embodiments, on a surface provided with an identification layer, the identification layer and the active material layer extend along a first direction. The identification layer includes at least two identification bands, and the at least two identification bands are spaced apart along a second direction. Both the first direction and the second direction are located on the surface and are perpendicular to each other. By arranging the identification layer as two spaced identification bands, and one of the identification bands can contact the active material layer, while ensuring rapid identification of the two sides of the battery electrode sheet, it can also play an insulating role on both sides of the active material layer.

[0012] In some exemplary embodiments, the identification layer is an insulating layer. By arranging the identification layer as an insulating layer, the identification layer coated on the electrode sheet body can not only realize the identification of the two sides of the battery electrode sheet, but also play an insulating and protective role on the active material layer on the electrode sheet body.

[0013] In some exemplary embodiments, the active material layer sequentially includes a conductive adhesive layer and an active layer on the surface; the identification layer is a conductive adhesive layer. For some battery electrode sheets, the active material layer thereon needs to first coat a conductive adhesive layer on the surface of the battery electrode sheet and then coat an active layer. In order to improve the coating efficiency of the battery electrode sheet, the identification layer is also set as a conductive adhesive layer. The conductive adhesive layer in the identification layer can be coated while coating the identification layer, thereby improving the processing efficiency of the battery electrode sheet. And setting the identification layer as a conductive adhesive layer reduces the types of coatings, and further reduces the preparatory work before coating.

[0014] In some exemplary embodiments, the electrode sheet body is a single-layer current collector or a composite current collector. Both the single-layer current collector and the composite current collector are used to collect the current generated by the battery active material so as to form a larger current for external output. Therefore, the current collector should be in full contact with the active material layer, and the internal resistance should be as small as possible.

[0015] According to another aspect of the present application, there is provided a method for coating a battery electrode sheet. The battery electrode sheet includes an electrode sheet body. The method for coating the battery electrode sheet includes: coating active materials on two surfaces of the electrode sheet body respectively to form active material layers; coating identification materials on at least one surface to form an identification layer, such that the shapes or positions of the coatings on the two surfaces are different.

[0016] An identification layer is formed by coating an identification material on at least one surface of the electrode sheet body, and the shapes or positions of the coatings on the two surfaces are made different, so as to accurately identify and distinguish the two surfaces of the electrode sheet body by the naked eye or a machine, ensuring that the battery electrode sheet can be accurately positioned and assembled in subsequent production.

[0017] In some exemplary embodiments, the identification material is coated only on one surface to form an identification layer. By coating an active material layer and an identification layer on one of the surfaces of the electrode sheet body, and only coating the active material layer on the other surface, the distinction and identification of the two sides of the battery electrode sheet are realized.

[0018] In some exemplary embodiments, the identification material is coated on the two surfaces respectively to form identification layers, and the shapes or positions of the identification layers on the two surfaces are different. By setting the shapes or positions of the identification layers on the two surfaces of the electrode sheet body to be different, the distinction and identification of the two sides of the battery electrode sheet are realized.

[0019] In some exemplary embodiments, active materials are coated on the two surfaces of the electrode sheet body respectively to form active material layers, including: coating the active materials on the two surfaces respectively along a first direction to form active material layers; coating an identification material on at least one surface to form an identification layer, including: coating the identification material on at least one surface along the first direction to form an identification layer, and the identification layer and the active material layer are arranged at intervals along a second direction, and the first direction and the second direction are both on the surface and perpendicular to each other. By coating the identification layer and the active material layer along the first direction, the neatness of the appearance of the battery electrode sheet is ensured, and it is convenient for coating the identification layer and the active material layer. By arranging the identification layer and the active material layer at intervals along the second direction, it can be avoided that the identification layer contacts the active material layer, making the identification layer not easy to identify, thus causing difficulty in distinguishing the two sides of the battery electrode sheet.

[0020] In some exemplary embodiments, active materials are coated on the two surfaces of the electrode sheet body respectively to form active material layers, including: coating the active materials on the two surfaces respectively along a first direction to form active material layers; coating an identification material on at least one surface to form an identification layer, including: coating the identification material on at least one surface along the first direction to form at least two identification bands, and the at least two identification bands are arranged at intervals along a second direction, and the first direction and the second direction are both on the surface and perpendicular to each other. By arranging the identification bands at the edges where the active material layers on the two sides of the battery electrode sheet are in contact, the insulation protection of both sides of the active material layer is realized, providing good working conditions for the active material layer, which is beneficial to increasing the service life of the battery electrode sheet and avoiding short-circuit faults of the battery electrode sheet. The identification bands on one side of the battery electrode sheet are arranged at intervals from the identification layer, ensuring the quick identification of the two sides of the battery electrode sheet.

[0021] In some exemplary embodiments, active material layers are formed by coating active materials on two surfaces of a pole piece body, including: successively coating conductive adhesive layer materials and active layer materials on the two surfaces to form active material layers; coating identification materials on at least one surface to form an identification layer, including: coating conductive adhesive layer materials on at least one surface to form an identification layer. For some battery pole pieces, the active material layer on them needs to coat the conductive adhesive layer on the surface of the battery pole piece first and then coat the active layer. In order to improve the coating efficiency of the battery pole piece, the identification layer is also set as a conductive adhesive layer, so that the identification layer can be coated while coating the conductive adhesive layer in the identification layer, thereby improving the coating efficiency of the battery pole piece. And setting the identification layer as a conductive adhesive layer reduces the types of coatings, and further reduces the preparatory work before coating.

[0022] According to another aspect of the present application, a battery pole piece coating device is provided. The battery pole piece includes a pole piece body. The battery pole piece coating device includes: a backing roller for driving the pole piece body to move; a coating structure disposed on one side of the backing roller for coating active materials on two surfaces of the pole piece body to form active material layers, and coating identification materials on at least one surface to form an identification layer, and the shapes or positions of the coatings on the two surfaces are different.

[0023] By setting the backing roller, the movement control of the battery pole piece is realized. Through the coating structure, active materials and identification materials are coated on the surface of the pole piece body, and the shapes or positions of the coatings on the two surfaces are different, so as to realize accurate identification and distinction of the two surfaces of the pole piece body by the naked eye or a machine, and ensure that the battery pole piece can be accurately positioned and assembled in production subsequently.

[0024] In some exemplary embodiments, the coating structure includes a first coating head. The first coating head is aligned with one side of the backing roller for coating the pole piece body on the backing roller. A first flow channel and a second flow channel are arranged in the first coating head. The first flow channel is used for flowing the active material, and the second flow channel is used for flowing the identification material. The first coating head is aligned with one side of the backing roller, so that the material extruded from the first coating head can be smoothly coated on the pole piece body. By arranging the first flow channel and the second flow channel separately in the first coating head, the first flow channel is used for flowing the active material, and the second flow channel is used for flowing the identification material, the simultaneous coating of the active material and the identification material is realized, thereby effectively ensuring the alignment degree between the identification material and the active material coated on the pole piece body, further improving the qualified rate of the production of the pole piece body, ensuring the neat appearance of the pole piece body, and facilitating the easy identification of both sides of the battery pole piece.

[0025] In some exemplary embodiments, the coating structure includes a second coating head that is aligned with one side of the back roller and is used to coat the electrode sheet body on the back roller; a third flow channel and a fourth flow channel are provided in the second coating head, the third flow channel is used for flowing the active material, and the fourth flow channel is used for flowing the identification material; a separation structure is provided at the outlet of the fourth flow channel, and the separation structure divides the outlet of the fourth flow channel into a spaced-apart first outlet and a second outlet, and the edge of the outlet of the third flow channel contacts the edge of the first outlet. By providing the third flow channel and the fourth flow channel in the second coating head, with the third flow channel for flowing the active material and the fourth flow channel for flowing the insulating material, simultaneous coating of the active material and the insulating material is achieved, ensuring the alignment and effectiveness of the contact between the identification tape and the active material layer on the electrode sheet body, and enabling the insulating material to provide reliable and effective insulation protection for the active material. By providing a separation structure at the outlet of the fourth flow channel to divide the outlet of the fourth flow channel into a spaced-apart first outlet and a second outlet, the flow channel structure inside the second coating head is effectively simplified, the mold opening cost of the second coating head is reduced, and by inputting the insulating material into the fourth flow channel, the insulating material forms spaced-apart identification tapes and identification layers on the electrode sheet body through the first outlet and the second outlet respectively, achieving simultaneous coating of the active material, the identification material, and the insulating material, ensuring the alignment among the three, and by using the same material for the insulating material and the identification material, the preliminary coating preparation work can be effectively simplified, and the coating efficiency of the battery electrode sheet can be improved.

[0026] In some exemplary embodiments, the separation structure is in the shape of a triangular prism, and one side surface of the separation structure is located on the plane where the outlet of the fourth flow channel is located. By setting the separation structure in the shape of a triangular prism and setting one of its side surfaces on the plane where the outlet of the fourth flow channel is located, it is ensured that one of the edges of the triangular prism faces the inside of the fourth flow channel, thereby reducing the pressure exerted on the separation structure by the material flowing in the fourth flow channel and ensuring the stability of the separation structure.

[0027] In some exemplary embodiments, the coating structure includes a first printing groove and a second printing groove that are circumferentially arranged on the annular side surface of the back roller, the first printing groove and the second printing groove are arranged at intervals, the first printing groove is used for accommodating the active material, and the second printing groove is used for accommodating the identification material. When the back roller rotates, it drives the electrode sheet body to move on its surface. Through the mutual contact between the active material in the first printing groove on the surface of the back roller and the identification material in the second printing groove and the electrode sheet body, simultaneous printing and coating of the active material and the identification material on the surface of the electrode sheet body are achieved, and the alignment of the coating of the active material and the identification material can be effectively ensured.

[0028] According to another aspect of the present application, there is also provided a battery cell, including the battery electrode sheet in any of the above embodiments.

[0029] The above description is only an overview of the technical solution of the present application. In order to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the following specific embodiments of the present application are given. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] By reading the following detailed description of the specific embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the specific embodiments and are not considered to be a limitation of the present application. And throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0031] Figure 1 is a schematic structural diagram of a vehicle provided by an embodiment of the present application;

[0032] Figure 2 is an exploded structural diagram of a battery provided by an embodiment of the present application;

[0033] Figure 3 is an exploded structural diagram of a battery cell provided by an embodiment of the present application;

[0034] Figure 4 is a schematic structural diagram of one side of a section of a battery electrode provided by an embodiment of the present application;

[0035] Figure 5 is a schematic structural diagram of the other side of a section of a battery electrode provided by an embodiment of the present application;

[0036] Figure 6 is a schematic structural diagram of one side of a section of a battery electrode provided by another embodiment of the present application;

[0037] Figure 7 is a schematic structural diagram of the other side of a section of a battery electrode provided by another embodiment of the present application;

[0038] Figure 8 is a schematic structural diagram of one side of a section of a battery electrode provided by another embodiment of the present application;

[0039] Figure 9 is a schematic structural diagram of the other side of a section of a battery electrode provided by another embodiment of the present application;

[0040] Figure 10 is a schematic sectional view of a battery electrode provided by another embodiment of the present application;

[0041] Figure 11 is a schematic flow chart of a method for coating a battery electrode provided by an embodiment of the present application;

[0042] Figure 12 Schematic flow diagram of the battery electrode coating method provided by another embodiment of the present application;

[0043] Figure 13 Schematic flow diagram of the battery electrode coating method provided by another embodiment of the present application;

[0044] Figure 14 Schematic flow diagram of the battery electrode coating method provided by another embodiment of the present application;

[0045] Figure 15 Schematic side view structure diagram of the battery electrode coating equipment provided by the embodiment of the present application;

[0046] Figure 16 Schematic top view structure diagram of the battery electrode coating equipment provided by the embodiment of the present application;

[0047] Figure 17 Schematic top view structure diagram of the battery electrode coating equipment provided by another embodiment of the present application;

[0048] Figure 18 Schematic structure diagram of the battery electrode coating equipment provided by another embodiment of the present application. Detailed implementation manners

[0049] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solutions of the present application more clearly, so they are only examples and cannot be used to limit the protection scope of the present application.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs; the terms used herein 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 accompanying drawings are intended to cover non-exclusive inclusion.

[0051] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of the present application, "a plurality" means more than two unless otherwise specifically defined.

[0052] Reference to "embodiments" in this document means that the specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0053] In the description of the embodiments of this application, the term "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can mean: the existence of A, the simultaneous existence of A and B, and the existence of B. In addition, the character " / " in this document generally indicates that the associated objects before and after are in an "or" relationship.

[0054] In the description of the embodiments of this application, the term "plurality" refers to two or more (including two). Similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to two or more pieces (including two pieces).

[0055] In the description of the embodiments of this application, the orientation or positional relationship indicated by technical terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation on the embodiments of this application.

[0056] In the description of the embodiments of this application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

[0057] With the development of technology and the increasingly wide application field of power batteries, batteries are required to have better and more powerful performance. The optimization of battery performance is largely achieved by asymmetrically coating active materials on both sides of the electrode sheets in the cell assembly.

[0058] The inventors of the present application noticed that in an automated production line, a large number of electrodes are produced, and after the two sides of the electrode are asymmetrically coated, it is impossible to directly distinguish and identify the two unevenly coated sides of the electrode by machine or naked eyes. As a result, the two unevenly coated sides of the battery electrode will be incorrectly distinguished, resulting in errors in the subsequent assembly of the battery electrode and unqualified battery production.

[0059] Based on this, the present application proposes a battery pole piece, a battery pole piece coating method, a battery pole piece coating device and a battery cell, wherein a coating is formed by combining an active material layer and an identification layer on the two surfaces of the pole piece body, and by setting the coatings on the two surfaces of the pole piece body to different shapes or positions, the two sides of the unevenly coated battery pole piece can be identified and distinguished, thereby ensuring the accuracy of the identification of the two sides of the battery pole piece.

[0060] The battery disclosed in the embodiments of the present application can be used in, but is not limited to, electrical devices such as vehicles, ships, or aircraft.

[0061] The embodiment of the present application provides an electric device using a battery as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0062] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0063] See also Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0064] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0065] Please refer to Figure 2 , Figure 2 which is an exploded structural schematic diagram of the battery 100 provided for some embodiments of the present application. The battery 100 includes a box body 10 and battery cells 20, and the battery cells 20 are accommodated in the box body 10. Among them, the box body 10 is used to provide an accommodation space for the battery cells 20, and the box body 10 can adopt various structures. In some embodiments, the box body 10 may include a first part 11 and a second part 12, the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define an accommodation space for accommodating the battery cells 20. The second part 12 may be a hollow structure with one end open, and the first part 11 may be a plate-like structure. The first part 11 covers the open side of the second part 12 so that the first part 11 and the second part 12 jointly define the accommodation space; the first part 11 and the second part 12 may also both be hollow structures with one side open, and the open side of the first part 11 covers the open side of the second part 12. Of course, the box body 10 formed by the first part 11 and the second part 12 can be of various shapes, such as a cylinder, a cuboid, etc.

[0066] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 can be connected in series, in parallel, or in a mixed connection. A mixed connection means that there are both series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 can be directly connected in series, in parallel, or in a mixed connection together, and then the whole formed by the multiple battery cells 20 is accommodated in the box body 10; of course, the battery 100 can also be that multiple battery cells 20 are first connected in series, in parallel, or in a mixed connection to form a battery module form, and then multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole and are accommodated in the box body 10. The battery 100 may further include other structures. For example, the battery 100 may further include a busbar component for realizing the electrical connection among the multiple battery cells 20.

[0067] Among them, each battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc.

[0068] Please refer to Figure 3 , Figure 3 which is a decomposition structural schematic diagram of the battery cell 20 in the battery 100 provided for some embodiments of the present application. The battery cell 20 refers to the smallest unit that makes up the battery. As Figure 3 , the battery cell 20 includes an end cap 21, a housing 22, a core component 23, and other functional components.

[0069] The end cap 21 refers to a component that covers the opening of the housing 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 21 can be adapted to the shape of the housing 22 to fit the housing 22. In some embodiments, the end cap 21 can be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, the end cap 21 is not easily deformed when subjected to extrusion and collision, enabling the battery cell 20 to have higher structural strength and improved safety performance. Functional components such as electrode terminals 21a can be provided on the end cap 21. The electrode terminals 21a can be used for electrical connection with the battery cell assembly 23 to output or input the electrical energy of the battery cell 20. In some embodiments, a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold can also be provided on the end cap 21. The material of the end cap 21 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not make special restrictions on this. In some embodiments, an insulating member can also be provided on the inner side of the end cap 21. The insulating member can be used to isolate the electrical connection components in the housing 22 from the end cap 21 to reduce the risk of short circuit. Exemplarily, the insulating member can be plastic, rubber, etc.

[0070] The housing 22 is a component used to cooperate with the end cap 21 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the battery cell assembly 23, the electrolyte, and other components. The housing 22 and the end cap 21 can be independent components. An opening can be provided on the housing 22, and the end cap 21 is covered at the opening to form the internal environment of the battery cell 20. Without limitation, the end cap 21 and the housing 22 can also be integrated. Specifically, the end cap 21 and the housing 22 can first form a common connection surface before other components are inserted into the housing, and when it is necessary to encapsulate the inside of the housing 22, the end cap 21 is then covered on the housing 22. The housing 22 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 22 can be determined according to the specific shape and size of the battery cell assembly 23. The material of the housing 22 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not make special restrictions on this.

[0071] The cell assembly 23 is the component in the battery cell 20 where the electrochemical reaction occurs. The housing 22 can contain one or more cell assemblies 23. The cell assembly 23 is mainly formed by winding or laminating a positive electrode sheet and a negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the main body of the cell assembly, and the parts of the positive electrode sheet and the negative electrode sheet without active materials respectively constitute the electrode tabs 23a. The positive electrode tab and the negative electrode tab can be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of the battery, the positive active material and the negative active material react with the electrolyte, and the electrode tabs 23a are connected to the electrode terminals to form a current loop.

[0072] According to one aspect of the embodiments of the present application, a battery electrode sheet is provided. For details, please refer to Figure 4 and Figure 5 , Figure 4 which shows the structure of one side of a section of the battery electrode sheet 231 provided in an embodiment of the present application. Figure 5 which shows the structure of the other side of a section of the battery electrode sheet 231 provided in an embodiment of the present application. The battery electrode sheet 231 includes a tab body 2310, and active material layers 2311 are respectively provided on two surfaces of the tab body 2310. The electrode sheet 231 further includes an identification layer 2312, and the identification layer 2312 is provided on at least one surface and makes the shapes or positions of the coatings on the two surfaces different.

[0073] Taking a lithium-ion battery as an example, the active material layers on the battery electrode sheet include a positive electrode material layer and a negative electrode material layer formed by coating. The positive electrode material generally can be lithium iron phosphate, and the negative electrode material generally can be materials such as natural graphite and artificial graphite. The identification layer 2312 can be formed by coating with a colloidal material that is easy to identify and insulating.

[0074] The coating on the surface of the tab body 2310 refers to the coating structure jointly composed of the active material layer 2311 and the identification layer 2312 on one surface of the tab body 2310. The shapes or positions of the coatings on the two surfaces being different can specifically be that the identification layer 2312 is only provided on one surface of the tab body 2310 and not provided on the other surface, so that the two surfaces of the tab body 2310 can be visually distinguished by the naked eye or a machine; the shapes or positions of the coatings on the two surfaces being different can also be that the identification layer 2312 is provided on both surfaces of the tab body 2310, but the shapes or positions of the identification layers 2312 provided on the two surfaces are different, so as to realize the identification and distinction of the two surfaces of the tab body 2310 by the naked eye or a machine.

[0075] By providing an identification layer 2312 on at least one surface of the electrode sheet body 2310 and making the shapes or positions of the coatings on the two surfaces different, accurate identification and differentiation of the two surfaces of the electrode sheet body 2310 can be achieved by the naked eye or a machine, ensuring that the battery electrode sheet 231 can be accurately positioned and assembled in subsequent production.

[0076] Please continue to refer to Figure 4 and Figure 5 , according to some embodiments of the present application, the identification layer 2312 is provided only on one surface of the electrode sheet body 2310.

[0077] By providing an active material layer 2311 and an identification layer 2312 on one of the surfaces of the electrode sheet body 2310, and only providing the active material layer 2311 on the other surface, the differentiation and identification of the two sides of the battery electrode sheet 231 are achieved.

[0078] Please refer to Figure 6 and Figure 7 , Figure 6 shows the structure of one side of a section of the battery electrode sheet 231 provided by another embodiment of the present application, Figure 7 shows the structure of the other side of a section of the battery electrode sheet 231 provided by another embodiment of the present application. According to some embodiments of the present application, identification layers 2312 are provided on both surfaces of the electrode sheet body 2310, and the shapes or positions of the identification layers 2312 on the two surfaces are different.

[0079] As Figure 6 and Figure 7 shown, the differentiation of the two sides of the battery electrode sheet 231 can be achieved by setting the positions and widths of the identification layers 2312 on the two surfaces of the electrode sheet body 2310 to be different.

[0080] It can be understood that in some other embodiments of the present application, the differentiation of the two sides of the battery electrode sheet 231 can also be achieved by setting the shapes of the identification layers 2312 on the two surfaces of the electrode sheet body 2310 to be different. For example, the identification layer 2312 on one side can be set as a strip-shaped rectangle, and the identification layer 2312 on the other side can be set as a strip-shaped wave. The specific shapes, positions, and sizes of the identification layers 2312 on the two surfaces of the electrode sheet body 2310 are not limited, as long as the two sides can be differentiated and identified.

[0081] By setting the shapes or positions of the identification layers 2312 on the two surfaces of the electrode sheet body 2310 to be different, the differentiation and identification of the two sides of the battery electrode sheet 231 are achieved.

[0082] Please refer to again Figure 4, According to some embodiments of the present application, on a surface of the electrode sheet body 2310 provided with an identification layer 2312, the identification layer 2312 and the active material layer 2311 extend along a first direction and are spaced apart along a second direction. The first direction and the second direction are both located on the surface of the electrode sheet body 2310 and are perpendicular to each other.

[0083] As Figure 4 shown, the first direction is the x-axis direction in the figure, and the second direction is the y-axis direction in the figure.

[0084] It should be noted that Figure 4 and Figure 5 only show the structure of a section of the battery electrode sheet 231. The battery electrode sheet 231 can be a wound battery electrode sheet or a stacked battery electrode sheet. The extending direction of the battery electrode sheet 231 (i.e., the extending direction of the identification layer 2312 and the active material layer 2311) is Figure 4 the x-axis direction in

[0085] Specifically, on the surface provided with the identification layer 2312, the identification layer 2312 can be spaced apart on both sides of the active material layer 2311 as Figure 4 shown. It can be understood that the identification layer 2312 can also be in contact with the active material layer 2311 or only spaced apart on one side of the active material layer 2311.

[0086] By extending the identification layer 2312 and the active material layer 2311 along the first direction, the neatness of the appearance of the battery electrode sheet 231 is ensured, and it is convenient for coating the identification layer 2312 and the active material layer 2311. By spacing the identification layer 2312 and the active material layer 2311 along the second direction, it can be avoided that the identification layer 2312 is in contact with the active material layer 2311, making the identification layer 2312 difficult to identify, thus causing difficulty in distinguishing between the two sides of the battery electrode sheet 231.

[0087] Please refer to Figure 8 and Figure 9 , Figure 8 which shows the structure of one side of a section of the battery electrode sheet 231 provided by another embodiment of the present application, Figure 9 and

[0088] As Figure 8As shown in FIG. 9, on one side of the battery electrode sheet 231, two spaced marking tapes 2313 are provided on each side of the active material layer 2311, and one of the marking tapes 2313 is in contact with the edge of the active material layer 2311. On the other side of the battery electrode sheet 231, one marking tape 2313 is provided on each side of the active material layer 2311, and the marking tape 2313 is arranged in contact with the edge of the active material layer 2311. By arranging the marking tapes 2313 in contact with the edges of the active material layer 2311 on both sides of the battery electrode sheet 231, insulation protection on both sides of the active material layer 2311 is achieved, providing good working conditions for the active material layer 2311, which is beneficial to increasing the service life of the battery electrode sheet 231 and avoiding short - circuit faults of the battery electrode sheet 231.

[0089] The marking tape 2313 can be made of a colloidal material with insulating properties, as long as it can ensure insulation protection for the edge of the active material layer 2311.

[0090] By setting the marking layer 2312 as two spaced marking tapes 2313, and one of the marking tapes 2313 can be in contact with the active material layer 2311, while ensuring quick identification of both sides of the battery electrode sheet 231, it can also play an insulating role on both sides of the active material layer 2311.

[0091] According to some embodiments of the present application, the marking layer 2312 is an insulating layer.

[0092] Specifically, the marking layer 2312 can use materials such as boehmite and alumina as the insulating main material, and materials such as polyvinylidene fluoride, styrene - butadiene rubber, polyacrylic acid, and polyamide as the colloidal material to form a coating with both marking ability and insulating ability.

[0093] By setting the marking layer 2312 as an insulating layer, the marking layer 2312 coated on the electrode sheet main body 2310 can not only identify both sides of the battery electrode sheet 231, but also play an insulating and protective role for the active material layer 2311 on the electrode sheet main body 2310.

[0094] Please refer to Figure 10 , the figure shows a cross - sectional structure of the battery electrode sheet 231 provided by another embodiment of the present application. According to some embodiments of the present application, the active material layer 2311 sequentially includes a conductive adhesive layer 2311a and an active layer 2311b on the surface of the electrode sheet main body 2310, and the marking layer 2312 is the conductive adhesive layer 2311a.

[0095] The conductive adhesive layer 2311a can use conductive carbon black as the conductive main material, and materials such as polyvinylidene fluoride, styrene - butadiene rubber, polyacrylic acid, and polyamide as the colloidal material.

[0096] For some battery electrodes 231, the active material layer 2311 on them needs to be coated with a conductive adhesive layer 2311a on the surface of the battery electrode 231 first and then coated with an active layer 2311b. To improve the coating efficiency of the battery electrode 231, the identification layer 2312 is also set as the conductive adhesive layer 2311a. The identification layer 2312 can be coated while coating the conductive adhesive layer 2311a in the identification layer 2312, thereby improving the processing efficiency of the battery electrode 231. And setting the identification layer 2312 as the conductive adhesive layer 2311a reduces the types of coatings, and thus reduces the preparatory work before coating.

[0097] According to some embodiments of the present application, the electrode substrate 2310 is a single-layer current collector or a composite current collector.

[0098] A current collector refers to a structure or component that collects current made of a metal foil, such as a copper foil, an aluminum foil, etc. The single-layer current collector is composed of one layer of metal foil, and the composite current collector is composed of multiple layers of metal foils laminated together.

[0099] Both the single-layer current collector and the composite current collector are used to collect the current generated by the battery active material so as to form a larger current for external output. Therefore, the current collector should be in full contact with the active material layer 2311, and the internal resistance should be as small as possible.

[0100] According to another aspect of the embodiments of the present application, a method for coating a battery electrode is provided. Specifically, please refer to FIG. 11, which shows the flow of the method for coating a battery electrode provided by an embodiment of the present application. Among them, the battery electrode includes an electrode substrate, and the method for coating a battery electrode includes:

[0101] S10: Coat active materials on two surfaces of the electrode substrate to form an active material layer;

[0102] S20: Coat identification materials on at least one surface to form an identification layer, so that the shapes or positions of the coatings on the two surfaces are different, thereby forming a battery electrode.

[0103] Specifically, the active material layer and the identification layer can be coated on the surface of the electrode substrate by the cooperation of a coating head and a back roller, or the active material layer and the identification layer can be coated by a back roller with a printing function.

[0104] By coating identification materials on at least one surface of the electrode substrate to form an identification layer, the shapes or positions of the coatings on the two surfaces are different, so as to realize accurate identification and distinction of the two surfaces of the electrode substrate by the naked eye or a machine, ensuring that the battery electrode can be accurately positioned and assembled in subsequent production.

[0105] According to some embodiments of the present application, the identification materials are coated on only one surface of the electrode substrate to form an identification layer.

[0106] By coating the active material layer and the identification layer on one of the surfaces of the electrode sheet body, and only coating the active material layer on the other surface, the distinction and identification of the two sides of the battery electrode sheet are realized.

[0107] According to some embodiments of the present application, identification materials are respectively coated on the two surfaces of the electrode sheet body to form identification layers, and the shapes or positions of the identification layers on the two surfaces are different.

[0108] By setting the shapes or positions of the identification layers on the two surfaces of the electrode sheet body to be different, the distinction and identification of the two sides of the battery electrode sheet are realized.

[0109] Please refer to Figure 12 , the figure shows the flow of the battery electrode sheet coating method provided by another embodiment of the present application. According to some embodiments of the present application, step S10 includes: S11: Coat active materials on the two surfaces of the electrode sheet body along the first direction to form active material layers;

[0110] Step S20 includes: S21: Coat identification materials on at least one surface of the electrode sheet body along the first direction to form an identification layer, and the identification layer and the active material layer are arranged at intervals along the second direction, and both the first direction and the second direction are located on the surface of the electrode sheet body and are perpendicular to each other.

[0111] By coating the identification layer and the active material layer along the first direction, the neatness of the appearance of the battery electrode sheet is ensured, and it is convenient for coating the identification layer and the active material layer. By arranging the identification layer and the active material layer at intervals along the second direction, it can be avoided that the identification layer contacts the active material layer, making the identification layer difficult to identify, thus causing difficulties in distinguishing the two sides of the battery electrode sheet.

[0112] Please refer to Figure 13 , the figure shows the flow of the battery electrode sheet coating method provided by another embodiment. According to some embodiments of the present application, step S10 includes: S12: Coat active materials on the two surfaces of the electrode sheet body along the first direction to form active material layers;

[0113] Step S20 includes: S22: Coat identification materials on at least one surface of the electrode sheet body along the first direction to form at least two identification bands, and the at least two identification bands are arranged at intervals along the second direction, and both the first direction and the second direction are located on the surface of the electrode sheet body and are perpendicular to each other.

[0114] By arranging the identification bands in contact with the edges of the active material layers on the two sides of the battery electrode sheet, the insulation protection on both sides of the active material layer is realized, providing good working conditions for the active material layer, which is beneficial to increasing the service life of the battery electrode sheet and avoiding short-circuit faults of the battery electrode sheet. The identification bands on one side of the battery electrode sheet are arranged at intervals from the identification layer, ensuring the quick identification of the two sides of the battery electrode sheet.

[0115] By coating the identification layer as two spaced-apart identification bands, and one of the identification bands can be coated in contact with the active material layer, while ensuring rapid identification of both sides of the battery electrode sheet, it can also insulate both sides of the active material layer.

[0116] Please refer to Figure 14 , which shows the flow of the battery electrode sheet coating method provided by another embodiment of the present application. According to some embodiments of the present application, step S10 includes: S13: Coating a conductive adhesive layer material and an active layer material on two surfaces of the electrode sheet body to form an active material layer.

[0117] Step S20 includes: S23: Coating a conductive adhesive layer material on at least one surface of the electrode sheet body to form an identification layer.

[0118] For some battery electrode sheets, the active material layer on them needs to be coated with a conductive adhesive layer on the surface of the battery electrode sheet first and then an active layer. In order to improve the coating efficiency of the battery electrode sheet, the identification layer is also set as a conductive adhesive layer, so that the identification layer can be coated while coating the conductive adhesive layer in the identification layer, thereby improving the coating efficiency of the battery electrode sheet, and setting the identification layer as a conductive adhesive layer reduces the types of coatings, and further reduces the preparatory work before coating.

[0119] According to another aspect of the embodiments of the present application, a battery electrode sheet coating device is also provided. Please specifically refer to Figure 15 , which shows the structure of the battery electrode sheet coating device 500 provided by an embodiment of the present application. The battery electrode sheet 231 includes an electrode sheet body 2310, and the battery electrode sheet coating device 500 includes: a back roller 510 and a coating structure 520. The back roller 510 is used to drive the battery electrode sheet 231 to move. The coating structure 520 is disposed on one side of the back roller 510 and is used to coat active materials on two surfaces of the electrode sheet body 2310 to form an active material layer 2311, and to coat identification materials on at least one surface to form an identification layer 2312, and the shapes or positions of the coatings on the two surfaces are different.

[0120] The back roller 510 is cylindrical, and the battery electrode sheet 231 is placed on the back roller 510, and the back roller 510 rotates to drive the battery electrode sheet 231 to move for coating.

[0121] The coating structure 520 has a coating outlet, and the coating outlet is aligned with one side of the back roller 510. By adding coating into the coating structure 520, the coating is extruded from the coating outlet under the push of pressure and coated on the battery electrode sheet 231.

[0122] By setting the backing roller 510, the movement control of the battery electrode sheet 231 is achieved. Through the coating structure 520, the active material and the identification material are coated on the surface of the electrode sheet body 2310, and the shapes or positions of the coatings on the two surfaces are made different, so as to achieve accurate identification and distinction of the two surfaces of the electrode sheet body 2310 by the naked eye or a machine, ensuring that the battery electrode sheet 231 can be accurately positioned and assembled in subsequent production.

[0123] In some embodiments of the present application, by providing a plurality of coating outlets on the coating structure 520, the active material and the identification material can be simultaneously coated on one side of the battery electrode sheet, reducing the consumption of time cost in the production of the battery electrode sheet, and effectively ensuring the relative positions of the active material and the identification material on the battery electrode sheet 231, thereby improving the qualification rate of the production of the battery electrode sheet 231.

[0124] Please refer to Figure 16 , which shows a top view structure of the first coating head 521 after being sectioned in the battery electrode sheet coating device 500 provided by an embodiment of the present application. According to some embodiments of the present application, the coating structure 520 includes a first coating head 521. The first coating head 521 is aligned with one side of the backing roller 510 and is used to coat the electrode sheet body 2310 on the backing roller 510. A first flow channel 5211 and a second flow channel 5212 are provided in the first coating head 521. The outlets of the first flow channel 5211 and the second flow channel 5212 are spaced apart. The first flow channel 5211 is used to circulate the active material, and the second flow channel 5212 is used to circulate the identification material.

[0125] Specifically, when coating one side of the electrode sheet body 2310, the active material is input into the first flow channel 5211, and the identification material is input into the second flow channel 5212. At the same time, the active material and the identification material are extruded from the outlets of the first flow channel 5211 and the second flow channel 5212 and coated on the electrode sheet body 2310 to achieve the simultaneous coating of the active material and the identification material. When coating the other side of the electrode sheet body 2310, only the active material is input into the first flow channel 5211, and the active material is extruded from the outlet of the first flow channel 5211 and coated on the electrode sheet body 2310 to achieve the coating of the active material on the other side of the electrode sheet body 2310.

[0126] The first coating head 521 is aligned with one side of the back roller 510, so that the material extruded from the first coating head 521 can be smoothly coated on the electrode sheet body 2310. By arranging the first flow channel 5211 and the second flow channel 5212 at intervals in the first coating head 521, the first flow channel 5211 is used for circulating the active material, and the second flow channel 5212 is used for circulating the identification material, so as to realize the simultaneous coating of the active material and the identification material, thereby effectively ensuring the alignment between the identification material and the active material coated on the electrode sheet body 2310, further improving the qualified rate of the production of the electrode sheet body 2310, ensuring the neat appearance of the electrode sheet body 2310, and facilitating the easy identification of both sides of the battery electrode sheet 231.

[0127] Please refer to Figure 17 , which shows the structure of the second coating head 522 after being sectioned in the battery electrode sheet coating device 500 provided by another embodiment of the present application. According to some embodiments of the present application, the coating structure 520 includes a second coating head 522, and the second coating head 522 is aligned with one side of the back roller 510 and is used for coating the electrode sheet body 2310 on the back roller 510. A third flow channel 5221 and a fourth flow channel 5222 are arranged in the second coating head 522. The third flow channel 5221 is used for circulating the active material, and the fourth flow channel 5222 is used for circulating the insulating material. A separating structure 5223 is arranged at the outlet of the fourth flow channel 5222. The separating structure 5223 divides the outlet of the fourth flow channel 5222 into a spaced first outlet 5224 and a second outlet 5225, and the edge of the outlet of the third flow channel 5221 contacts the edge of the first outlet 5224.

[0128] Specifically, after the insulating material is input into the fourth flow channel 5222, the insulating material is extruded through the first outlet 5224 and the second outlet 5225, and two identification bands 2313 are respectively formed on the electrode sheet body 2310.

[0129] The separating structure 5223 can be integrally formed with the housing of the second coating head 522, ensuring the structural strength of the separating structure 5223 and avoiding the fracture of the separating structure 5223 due to excessive extrusion pressure of the insulating material.

[0130] By providing a third flow channel 5221 and a fourth flow channel 5222 within the second coating head 522, with the third flow channel 5221 for flowing the active material and the fourth flow channel 5222 for flowing the insulating material, simultaneous coating of the active material and the insulating material is achieved, ensuring the alignment and effectiveness of the contact between the identification tape 2313 and the active material layer 2311 on the main electrode sheet 2310, and enabling the insulating material to provide reliable and effective insulation protection for the active material. By providing a separation structure 5223 at the outlet of the fourth flow channel 5222 to divide the outlet of the fourth flow channel 5222 into spaced-apart first outlet 5224 and second outlet 5225, the flow channel structure inside the second coating head 522 is effectively simplified, reducing the mold opening cost of the second coating head 522. Moreover, by inputting the insulating material into the fourth flow channel 5222, the insulating material forms spaced-apart identification tape 2313 and identification layer 2312 on the main electrode sheet 2310 through the first outlet 5224 and the second outlet 5225 respectively, achieving simultaneous coating of the active material, the identification material, and the insulating material, ensuring the alignment among the three. And by using the same material for the insulating material and the identification material, the preliminary coating preparation work can be effectively simplified, improving the coating efficiency of the battery electrode sheet 231.

[0131] Please continue to refer to Figure 17 , according to some embodiments of the present application, the separation structure 5223 is in the shape of a triangular prism, and one side surface is located on the plane where the outlet of the fourth flow channel 5222 is located.

[0132] By setting the separation structure 5223 in the shape of a triangular prism and setting one of its side surfaces on the plane where the outlet of the fourth flow channel 5222 is located, it is ensured that one of the edges of the triangular prism faces the inside of the fourth flow channel 5222, thereby reducing the pressure exerted on the separation structure 5223 by the material flowing in the fourth flow channel 5222 and ensuring the stability of the separation structure 5223.

[0133] Please refer to Figure 18 , the figure shows the structure of the battery electrode sheet coating device 500 provided by another embodiment of the present application. According to some embodiments of the present application, the coating structure 520 includes a first printing groove 523 and a second printing groove 524 circumferentially arranged on the annular side surface of the back roller 510. The first printing groove 523 and the second printing groove 524 are arranged at intervals. The first printing groove 523 is used to accommodate the active material, and the second printing groove 524 is used to accommodate the identification material.

[0134] During the process of coating the battery electrode sheet 231, active material is disposed in the first printing groove 523, and identification material is disposed in the second printing groove 524. Considering that the active material and the identification material may drip during the rotation of the back roller 510, the first printing groove 523 and the second printing groove 524 can be set to have a smaller depth, and the active material and the identification material are coated on the surfaces of the first printing groove 523 and the second printing groove 524 to form a thinner layer. Alternatively, a material accommodating box can be provided at the bottom of the back roller 510 so that the dripping material is collected in the accommodating box for secondary utilization.

[0135] When the back roller 510 rotates, it drives the main body 2310 of the electrode sheet to move on its surface. Through the mutual contact between the active material in the first printing groove 523 on the surface of the back roller 510 and the identification material in the second printing groove 524 and the main body 2310 of the electrode sheet, simultaneous printing and coating of the active material and the identification material on the surface of the main body 2310 of the electrode sheet are achieved, and the alignment of the coating of the active material and the identification material can be effectively ensured.

[0136] For the above embodiment in which the active material includes a conductive adhesive layer material and an active layer material, during the first printing and coating, the conductive adhesive layer material can be disposed in both the first printing groove 523 and the second printing groove 524, and the conductive adhesive layer material printed and coated on the main body 2310 of the electrode sheet through the second printing groove 524 is used as the identification material. During the second printing and coating, only the active material is disposed in the first printing groove 523 to achieve the printing and coating of the active material on the surface of the conductive adhesive layer material.

[0137] According to another aspect of the embodiments of the present application, a battery cell is provided, including the above battery electrode sheet 231.

[0138] In the battery cell, by providing an active material layer 2311 and an identification layer 2312 on one side of the battery electrode sheet 231, and only providing the active material layer 2311 on the other side, the distinction and identification of the two sides of the battery electrode sheet 231 are achieved. And by disposing the identification layer 2312 on at least one side of the active material layer 2311 and being spaced apart from the active material layer 2311, it is convenient for machines or humans to distinguish and identify the two sides of the battery electrode sheet 231. The extending directions of the identification layer 2312 and the active material layer 2311 are arranged parallel to each other, ensuring the stability of the active material layer 2311 when the battery electrode sheet 231 works, and effectively preventing the identification layer 2312 from being mixed with the active material layer 2311 and causing a decrease or even failure of the performance of the active material layer 2311.

[0139] 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 foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered within the scope of the claims and the description of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery electrode, characterized in that, the battery electrode includes an electrode body, and active material layers are respectively arranged on two surfaces of the electrode body; and further includes an identification layer; the identification layer is arranged on the two surfaces, and the shapes or positions of the coatings on the two surfaces are different, wherein the shapes or positions of the identification layers on the two surfaces are different.

2. The battery electrode according to claim 1, on one of the surfaces provided with the identification layer, the identification layer and the active material layer extend along a first direction and are spaced apart along a second direction, and the first direction and the second direction are both located on the surface and are perpendicular to each other.

3. The battery electrode according to claim 1, on one of the surfaces provided with the identification layer, the identification layer and the active material layer extend along a first direction, the identification layer includes at least two identification bands, and at least two of the identification bands are spaced apart along a second direction, and the first direction and the second direction are both located on the surface and are perpendicular to each other.

4. The battery electrode according to claim 1, the identification layer is an insulating layer.

5. The battery electrode according to claim 1, the active material layer sequentially includes a conductive adhesive layer and an active layer on the surface; the identification layer is a conductive adhesive layer.

6. The battery electrode according to claim 1, the electrode body is a single-layer current collector or a composite current collector.

7. A battery electrode coating device, characterized in that, the battery electrode includes an electrode body, including: a back roller for driving the electrode body to move; a coating structure arranged on one side of the back roller, for respectively coating active materials on two surfaces of the electrode body to form active material layers, and coating identification materials on the two surfaces to form an identification layer, and the shapes or positions of the coatings on the two surfaces are different, wherein the shapes or positions of the identification layers on the two surfaces are different.

8. The battery electrode coating device according to claim 7, the coating structure includes a first coating head, and the first coating head is aligned with one side of the back roller for coating the electrode body on the back roller; a first flow channel and a second flow channel are arranged in the first coating head, the first flow channel is used for flowing the active material, and the second flow channel is used for flowing the identification material.

9. The battery electrode coating device according to claim 7 or 8, the coating structure includes a second coating head, and the second coating head is aligned with one side of the back roller for coating the electrode body on the back roller; a third flow channel and a fourth flow channel are arranged in the second coating head, the third flow channel is used for flowing the active material, and the fourth flow channel is used for flowing the identification material; a separating structure is arranged at the outlet of the fourth flow channel, and the separating structure divides the outlet of the fourth flow channel into a separated first outlet and a second outlet, and the edge of the outlet of the third flow channel is in contact with the edge of the first outlet.

10. The battery electrode coating device according to claim 9, wherein the partition structure is in the shape of a triangular prism, and one side surface of the partition structure is located on the plane where the outlet of the fourth flow channel is located.

11. The battery electrode coating device according to any one of claims 7 or 8, wherein the coating structure includes a first printing groove and a second printing groove arranged circumferentially on the annular side surface of the back roller, the first printing groove and the second printing groove are arranged at intervals, the first printing groove is used to accommodate the active material, and the second printing groove is used to accommodate the marking material.

12. A battery cell, comprising the battery electrode according to any one of claims 1-6.

Images