Electrode sheet and battery

Abstract

The present application discloses an electrode sheet and a battery. The electrode sheet includes a current collector and an active material layer arranged on the surface of the current collector, the active material layer includes two or more active material layer units, and each active material layer unit is arranged on the surface of the current collector at equal intervals from each other; a conductive separator layer is filled between two adjacent active material layer units, and the conductive separator layer is connected to the current collector. The electrode sheet separates each active material layer unit by adding a conductive separator layer in the active material layer. The conductive separator layer can effectively act as a "micro-current collector" in the active material layer or can serve as an extension of the current collector into the active material layer, forming a conductive channel in the active material layer, thereby significantly improving the transmission capacity of active ions and electrons, significantly reducing the resistance and polarization phenomenon of the electrode sheet, and improving the rate performance of the electrode sheet. The battery contains the electrode sheet.

Description

Technical Field

[0001] The present application belongs to the field of batteries, and specifically relates to an electrode sheet and a battery. Background Art

[0002] With the transformation of global energy structure and the improvement of environmental awareness, new energy vehicles and large-scale energy storage technologies have developed rapidly. These emerging technology fields have put forward higher requirements on battery performance, especially energy density and cycle performance.

[0003] As a widely adopted electrode design strategy, thick electrode preparation technology significantly improves the energy density of the battery by simply and controllably increasing the thickness of the active material layer. However, as the thickness of the electrode increases, the diffusion distance of active ions and the transmission distance of electrons also increase accordingly, which leads to a serious reduction in the electrode rate performance. In addition, thicker active material layers are more likely to produce internal expansion stress, which may cause the electrode structure to collapse and affect the cycle life of the battery. Therefore, this paradox between energy density and rate performance and cycle life in thick electrode technology has limited the technology to a certain extent in practical applications.

[0004] In order to overcome the shortcomings of thick electrode technology, some existing methods attempt to improve the rate performance of electrodes. For example, by optimizing the particle size and distribution of electrode materials, the diffusion resistance of lithium ions inside the electrode is reduced; or by introducing conductive additives, the electronic conductivity of the electrode is improved. However, these methods can often only improve the rate performance to a certain extent, and cannot completely solve the contradiction between energy density and rate performance and cycle life faced by thick electrode technology. In addition, these methods may also bring about problems such as rising costs and complex processes, which are not conducive to the large-scale production and application of lithium-ion batteries.

[0005] Therefore, designing a new thick electrode structure to improve the rate performance of the electrode while meeting the high energy density requirements has become an urgent problem to be solved in the current field of lithium-ion battery technology. Utility Model Content

[0006] The purpose of the present application is to overcome the above-mentioned deficiencies of the prior art and to provide a thick electrode sheet and a battery containing the thick electrode sheet, so as to solve the technical problems of the unsatisfactory rate performance and cycle performance of the existing thick electrode.

[0007] In order to achieve the above application purpose, the first aspect of the embodiment of the present application provides an electrode sheet. The electrode sheet of the embodiment of the present application includes a current collector and an active material layer arranged on the surface of the current collector, the active material layer includes more than two active material layer units, and each of the active material layer units is arranged on the surface of the current collector at equal intervals; a conductive separator layer is filled between two adjacent active material layer units, and the conductive separator layer is connected to the current collector.

[0008] In some embodiments, the active material layer units are arranged on the surface of the current collector at intervals along the length direction of the current collector; or

[0009] In some embodiments, the active material layer units are arranged on the surface of the current collector at intervals along the width direction of the current collector; or

[0010] In some embodiments, the conductive separation layer is in a grid structure surrounding each of the active material layer units.

[0011] In some embodiments, the conductive separation layer includes one or more of the following (1) to (4):

[0012] (1) The width of the conductive separation layer is 5 to 20 μm;

[0013] (2) The thickness of the conductive separator layer is 100 to 300 μm;

[0014] (3) The filling material of the conductive separation layer includes at least one of carbon black, acetylene black, Ketjen black, carbon nanotubes, graphene, aluminum metal particles, copper metal particles and nickel metal particles;

[0015] (4) The amount of elastic deformation of the conductive separation layer is greater than the amount of elastic deformation of the active material layer unit.

[0016] In some embodiments, the conductive separator layer contains a porous structure.

[0017] In some embodiments, the conductive separation layer has the same thickness as the active material layer.

[0018] In some embodiments, the current collector has a thickness of 10 to 30 μm.

[0019] In some embodiments, the thickness of the active material layer unit is 100-300 μm.

[0020] In some embodiments, the width of the active material layer unit is 50-100 μm.

[0021] In some embodiments, the current collector has two opposite surfaces, and the active material layer and the conductive separator layer are disposed on both surfaces.

[0022] In the embodiment, the thickness of each active material layer is 100-200 μm.

[0023] According to a second aspect of the embodiment of the present application, a battery is provided. The battery of the embodiment of the present application includes an electrode of the embodiment of the present application.

[0024] Compared with the prior art, the embodiments of the present application have the following technical effects:

[0025] The electrode of the embodiment of the present application separates each active material layer unit by adding a conductive separator layer in the active material layer and filling it between two adjacent active material layer units. In this way, the conductive separator layer can effectively act as a "micro-current collector" in the active material layer or can serve as an extension of the current collector into the active material layer, forming a conductive channel in the active material layer, thereby significantly improving the transmission capacity of active ions and electrons, reducing the internal resistance of the active material layer, significantly reducing the resistance and polarization phenomenon of the electrode, and improving the rate performance of the electrode.

[0026] The battery of the embodiment of the present application contains the electrode of the embodiment of the present application, and therefore, the battery of the embodiment of the present application has high rate performance and cycle performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 This is a schematic diagram of the structure of the electrode in the embodiment of the present application;

[0029] Figure 2 for Figure 1 A top view of a structure of an active material layer contained in an electrode sheet of an embodiment of the present application is shown;

[0030] Figure 3 for Figure 1 A top view of another structure of the active material layer contained in the electrode sheet of the embodiment of the present application is shown;

[0031] Figure 4 for Figure 1 A top view of another structure of the active material layer contained in the electrode sheet of the embodiment of the present application is shown;

[0032] Figure 5 The figure is a schematic flow chart of a method for preparing an electrode sheet according to an embodiment of the present application.

[0033] The reference numerals in the specific implementation manner are as follows:

[0034] 1-current collector;

[0035] 2-active material layer, 21-active material layer unit, 22-conductive separator layer. DETAILED DESCRIPTION

[0036] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0037] In this application, the term "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0038] In this application, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple, respectively.

[0039] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0040] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0041] The weight of the relevant components mentioned in the embodiment description of the present application can not only refer to the specific content of each component, but also represent the proportional relationship between the weights of the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the embodiment description of the present application, it is within the scope disclosed in the embodiment description of the present application. Specifically, the mass described in the embodiment description of the present application can be a mass unit known in the chemical industry such as μg, mg, g, kg, etc.

[0042] In a first aspect, the present application provides an electrode. As some embodiments of the present application, the structure of the electrode sheet of the present application embodiment is as follows: Figures 1 to 4 As shown, it includes a current collector 1 and an active material layer 2 arranged on the surface of the current collector 1. The active material layer 2 includes more than two active material layer units 21 and a conductive separator layer 22, and each active material layer unit 21 is arranged on the surface of the current collector 1 at equal intervals; the conductive separator layer 22 is filled between two adjacent active material layer units 21, and the conductive separator layer 22 is connected to the current collector 1.

[0043] In the electrode sheet of the embodiment of the present application, the active material layer 2 refers to a layer structure containing electrode active materials. The active material layer 2 is arranged on the surface of the current collector 1 and can be stacked. Of course, when the current collector 1 is a pore-expanding structure, the side of the active material layer 2 close to the surface of the current collector 1 can be partially embedded in the current collector 1. The conductive separator layer 22 is filled between two adjacent active material layer units 21 arranged at intervals, which is equivalent to the conductive separator layer 22 playing a role of separation, dividing the entire active material layer 2 into several intervals, and the active material layer in each interval is an active material layer unit 21. The conductive separator layer 21 is connected to the current collector 1, which means that there is electron flow between the two, that is, it has electrical conductivity. The active material layer units 21 are arranged on the surface of the current collector 1 at equal intervals from each other, which means that the spacing between two adjacent active material layer units 21 is equal.

[0044] The electrode sheet of the embodiment of the present application is provided with a conductive separation layer 22 in the active material layer 2 for separating each active material layer unit 21. In this way, the conductive separation layer 22 can effectively act as a "micro-current collector" in the active material layer 2 or can serve as an extension of the current collector 1 into the active material layer 2, forming a conductive channel in the active material layer 2, thereby significantly improving the transmission capacity of active ions and electrons, reducing the internal resistance of the active material layer 2, significantly reducing the resistance and polarization phenomenon of the electrode sheet, and improving the rate performance of the electrode sheet.

[0045] [current collector]

[0046] The electrode sheet of the present application embodiment contains Figures 1 to 4The current collector 1 in the embodiment refers to a structure for collecting current and transmitting electrons. It can be a current collector for an existing electrode sheet or a current collector improved based on an existing current collector. In some embodiments, the thickness of the current collector 1 can be 10 to 30 μm. It can be adjusted according to the process conditions. This thickness range can effectively improve the mechanical properties of the electrode sheet.

[0047] In some embodiments, the current collector 1 may be in the shape of a sheet or other shapes, and may be a solid structure or a porous structure.

[0048] In some embodiments, when the current collector 1 is in sheet shape, the current collector 1 has two surfaces disposed opposite to each other. In this case, at least one of the two surfaces disposed opposite to each other contained in the current collector 1 is provided with the active material layer 2. Based on the consideration of the gram capacity of the electrode sheet, the two surfaces disposed opposite to each other contained in the current collector 1 are both provided with the active material layer 2.

[0049] In addition, depending on the type of electrode sheet, the material and type of the current collector 1 may also be different. For example, when the electrode sheet is a positive electrode, the current collector 1 may be a positive electrode current collector; when the electrode sheet is a negative electrode, the current collector 1 may be a negative electrode current collector.

[0050] In some embodiments, the current collector 1 may include but is not limited to metal or composite current collectors. When it is a composite current collector, the composite current collector may include a composite material of a polymer material and a metal. When it is a metal current collector, the metal may be commonly used, aluminum, aluminum alloy or other conductive metals. It may also be a non-conductive current collector, such as carbon fiber, carbon nanotube (CNT), graphite, etc.

[0051] [Active material layer]

[0052] In the electrode sheet of the present application, the electrode sheet contains Figures 1 to 4 The active material layer 2 shown includes more than two active material layer units 21 and a conductive separator layer 22. Among them, since the conductive separator layer 22 is filled between two adjacent active material layer units 21, the conductive separator layer 22 divides the entire active material layer 2 into several active material layer units 21, and plays the role of separating two adjacent active material layer units 21. Moreover, the conductive separator layer 22 itself is conductive and connected to the current collector 1. Therefore, the conductive separator layer 22 plays the role of a "micro-current collector" in the active material layer 2, or acts as an extension of the current collector 1 into the active material layer 2. In this way, the conductive separator layer 22 can transmit electrons in each active material layer unit 21 and collect them to the current collector 1. Compared with traditional electrodes, especially compared with existing thick electrodes, it can significantly reduce the resistance of the active material layer 2 and significantly improve the conductivity of the active material layer 2, so that the electrode sheet rate performance is significantly improved.

[0053] In some embodiments, the active material layer units 21 and the conductive separator layers 22 are alternately arranged on the surface of the current collector 1 along the length direction of the current collector, such as Figure 2 Specifically, each active material layer unit 21 is arranged side by side on the surface of the current collector 1 along the length direction of the current collector 1 (that is, the length direction of the electrode sheet), and at this time, the conductive separation layer 22 is also arranged side by side on the surface of the current collector 1 along the length direction of the current collector 1, and is filled between two adjacent active material layer units 21, and is connected to the current collector 1.

[0054] In some embodiments, the active material layer units 21 and the conductive separator layers 22 are alternately arranged on the surface of the current collector 1 along the width direction of the current collector, such as Figure 3 Specifically, each active material layer unit 21 is arranged side by side on the surface of the current collector 1 along the width direction of the current collector 1 (that is, the width direction of the electrode sheet), and at this time, the conductive separation layer 22 is also arranged side by side on the surface of the current collector 1 along the width direction of the current collector 1, and is filled between two adjacent active material layer units 21, and is connected to the current collector 1.

[0055] In some embodiments, the active material layer units 21 are arranged on the surface of the current collector 1 in a block array, such as Figure 3 At this time, the conductive separator layer 22 surrounds each active material layer unit 21 in a grid structure. At this time, the conductive separator layer 22 forms a conductive network structure in the active material layer 2, which can significantly reduce the resistance of the active material layer 2 and significantly improve the conductivity and rate capability of the electrode sheet.

[0056] In the above-mentioned embodiments, the active material layer unit 21 and the conductive separator layer 22 are arranged on the surface of the current collector 1. The conductive separator layer 22 can act as a "micro-current collector" in the active material layer 2 or as an extension of the current collector 1 into the active material layer 2, and can significantly reduce the resistance of the active material layer 2, significantly improve the conductivity of the active material layer 2, and significantly improve the rate performance of the electrode sheet. In addition, the thickness of the active material layer 2 can be increased, thereby increasing the capacity density of the electrode sheet.

[0057] The above Figures 2 to 4 The figure is only an example of the arrangement of the active material layer unit 21 and the conductive separator layer 22 on the surface of the current collector 1. The arrangement of the active material layer unit 21 and the conductive separator layer 22 on the surface of the current collector 1 may also be other arrangements. Figures 2 to 4 The settings shown, or based on Figures 2 to 4 Other configurations such as the evolution of the configuration shown are all within the scope of the electrode sheet disclosed in the embodiments of the present application.

[0058] In some embodiments, the thickness of a single active material layer unit 21 is 100-300 μm. In exemplary embodiments, the thickness may be 100 μm, 130 μm, 150 μm, 180 μm, 200 μm, 230 μm, 250 μm, 280 μm, 300 μm, or other typical but non-limiting thicknesses or a range between any two thickness values.

[0059] In the embodiment, when the current collector 1 is a sheet-shaped current collector, the current collector 1 has two surfaces arranged opposite to each other. At this time, when the two surfaces are both provided with active material layers 2, the thickness of the single active material layer unit 21 can be set to 100-200 μm.

[0060] In the embodiment, when the current collector 1 is a sheet-shaped current collector or other morphology, and an active material layer 2 is disposed on one surface of the current collector 1, the thickness of the single active material layer unit 21 can be set to be ≥300 μm.

[0061] Since the active material layer 2 contains the conductive separator layer 22, the active material layer 2 can be set relatively thick, such as 300 μm, or thicker, thereby increasing the content of electrode active materials in the active material layer 2 and significantly improving the capacity density of the electrode sheet.

[0062] In some embodiments, the width of a single active material layer unit 21 may be 50 to 100 μm, preferably 50 to 70 μm, and in exemplary embodiments, may be 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, or other typical but non-limiting widths or a range between any two width values. Figure 2 and 3 When the distribution is shown, the width refers to the distance between two adjacent conductive separation layers 22; Figure 4 When the block array is distributed as shown, the width can also be understood as the length of a single block of active material layer unit 21. By controlling the width of a single active material layer unit 21, the line width of the conductive separator layer 22 can be indirectly adjusted, thereby giving full play to the role of the conductive separator layer 22 as a "micro-current collector" or acting as an extension of the current collector 1 into the active material layer 2, thereby increasing the volume or mass proportion of the active material layer unit 21 in the electrode sheet, thereby increasing the capacity density of the electrode sheet.

[0063] In the embodiment, the material contained in each active material layer unit 21 may be a material of a conventional electrode active material layer, such as a conductive agent, a binder, etc. in addition to the electrode active material. The electrode active material may include at least one of positive electrode active materials such as lithium iron phosphate, ternary materials, lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, etc., or may include at least one of negative electrode active materials such as graphite, silicon-based materials, lithium titanate, etc.

[0064] In some embodiments, the thickness of the conductive separator layer 22 in the above embodiments can be 100-300 μm, and can be 150-250 μm. In the exemplary embodiment, it can be 100 μm, 130 μm, 150 μm, 180 μm, 200 μm, 230 μm, 250 μm, 280 μm, 300 μm, etc., which are typical but non-limiting thicknesses or ranges between any two thickness values. The thickness of the conductive separator layer 22 can be equal to the thickness of the above-mentioned single active material layer unit 21, so that the surface of the electrode sheet can be flat, and the electrochemical properties of the electrode sheet, such as the cycle performance, can be improved.

[0065] In some embodiments, the width of the conductive separation layer 22 in the above embodiments is 5-20 μm, preferably 5-10 μm. In the exemplary embodiment, it can be 5 μm, 8 μm, 10 μm, 12 μm, 15 μm, 18 μm, 20 μm, and other typical but non-limiting widths or a range between any two width values. Figure 2 and 3 When the distribution mode is shown, the width refers to the distance between two adjacent active material layer units 21; Figure 4 When the block array is distributed as shown, the width is the line width of the grid structure. By controlling the width of the conductive separator layer 22, the conductive separator layer 22 can play the role of a "micro-current collector" or an extension of the current collector 1 into the active material layer 2, and at the same time increase the volume or mass proportion of the active material layer unit 21 in the electrode sheet, thereby increasing the capacity density of the electrode sheet.

[0066] In the embodiment, the thickness of the conductive separator layer 22 is the same as the thickness of the active material layer 21. In this way, the surface of the electrode sheet of the embodiment of the present application can be flat, and when it is assembled into an electrode assembly with a separator, the volume density of the electrode assembly and the cycle stability of the battery can be improved.

[0067] In some embodiments, when subjected to the same force, the elastic deformation of the conductive separator layer 22 is greater than the elastic deformation of the active material layer unit 21. In this way, in the embodiment of the present application, during the charge and discharge process, when the electrode active material in the active material layer unit 21 undergoes volume expansion during the process of inserting and extracting active ions, which causes the volume expansion of the active material layer unit 21, since the elastic deformation of the conductive separator layer 22 is greater than that of the active material layer unit 21, at this time, the conductive separator layer 22 will be subjected to the squeezing force that causes the volume expansion of the active material layer unit 21 and undergo a certain deformation, thereby playing a buffering role, absorbing the volume expansion of the active material layer unit 21, so that the overall structural stability of the active material layer 2 is significantly improved, thereby significantly improving the structural stability of the electrode sheet during the charge and discharge process, and significantly improving the cycle performance of the electrode sheet.

[0068] In an embodiment, when the elastic deformation of the conductive separation layer 22 is greater than the elastic deformation of the active material layer unit 21, the conductive separation layer 22 may be a conductive organic body, such as a conductive separation layer formed by a conductive polymer; or a conductor containing organic matter, such as a conductive separation layer formed by a mixture containing a conductive agent and a binder.

[0069] In some embodiments, the conductive separator layer 22 contains a porous structure. In this case, the porous structure can act as a volume buffer space. In this way, in the embodiment of the present application, when the electrode active material in the active material layer unit 21 expands in volume during the process of inserting and extracting active ions, which causes the active material layer unit 21 to expand in volume, the porous structure contained in the conductive separator layer 22 can effectively act as a volume accommodating space, absorbing the volume expansion of the active material layer unit 21, so that the overall structural stability of the active material layer 2 is significantly improved, thereby significantly improving the structural stability of the electrode sheet during the charge and discharge process, so that the cycle performance of the electrode sheet is significantly improved.

[0070] In an embodiment, when the conductive separator layer 22 has a porous structure, the material of the conductive separator layer 22 can be three-dimensional conductive particles, two-dimensional conductive sheets, or one-dimensional conductive linear materials. In an exemplary embodiment, the material of the conductive separator layer 22 is at least one of carbon black, acetylene black, Ketjen black, carbon nanotubes, graphene, nickel metal particles, aluminum metal particles (positive electrode), copper metal particles (negative electrode), etc. These conductive materials have high electrical conductivity and can make the conductive separator layer 22 have a porous structure.

[0071] Based on the current collector and active material layer solutions contained in the electrode sheets of the above-mentioned embodiments, the electrode sheets of the embodiments of the present application can at least be the following electrode sheets:

[0072] In the exemplary embodiment, the electrode sheet is a positive electrode sheet, which contains a 20μm aluminum foil current collector, and an active material layer is laminated on two opposite surfaces. The active material layer contains more than two active material layer units, and each active material layer unit is laminated and bonded on the surface of the aluminum foil current collector at intervals; the width of a single active material layer unit is 50μm; the spacing between two adjacent active material layer units is 10μm, and Ketjen black is filled between two adjacent active material layer units to form a conductive separation layer. The active material layer unit is a 200μm thick LiCoO2 active material layer.

[0073] In the exemplary embodiment, the electrode sheet is a positive electrode sheet, which contains a 20μm aluminum foil current collector, and an active material layer is laminated on two opposite surfaces. The active material layer contains more than two active material layer units, and each active material layer unit is laminated and bonded on the surface of the aluminum foil current collector at intervals; the width of a single active material layer unit is 80μm; the spacing between two adjacent active material layer units is 15μm, and Ketjen black is filled between two adjacent active material layer units to form a conductive separation layer. The active material layer unit is a 300μm thick LiCoO2 active material layer.

[0074] In the exemplary embodiment, the electrode sheet is a positive electrode sheet, which contains a 20μm aluminum foil current collector, and an active material layer is laminated on two opposite surfaces. The active material layer contains more than two active material layer units, and each active material layer unit is laminated and bonded on the surface of the aluminum foil current collector at intervals; the width of a single active material layer unit is 50μm; the spacing between two adjacent active material layer units is 10μm, and carbon nanotubes are filled between two adjacent active material layer units to form a conductive separation layer. The active material layer unit is a 200μm thick LiCoO2 active material layer.

[0075] In the exemplary embodiment, the electrode sheet is a positive electrode sheet, which contains a 20μm aluminum foil current collector, and an active material layer is laminated on two opposite surfaces. The active material layer contains more than two active material layer units, and each active material layer unit is laminated and bonded to the surface of the aluminum foil current collector at intervals; the width of a single active material layer unit is 50μm; the spacing between two adjacent active material layer units is 10μm, and Ketjen black is filled between two adjacent active material layer units to form a conductive separation layer. The active material layer unit is a 200μm thick LiNi 0.8 Co 0.15 Al 0.05 O2 ternary material active material layer.

[0076] In the exemplary embodiment, the electrode sheet is a positive electrode sheet, which contains a 20μm aluminum foil current collector, and an active material layer is laminated on two opposite surfaces. The active material layer contains more than two active material layer units, and each active material layer unit is laminated and bonded to the surface of the aluminum foil current collector at intervals; the width of a single active material layer unit is 80μm; the spacing between two adjacent active material layer units is 15μm, and Ketjen black is filled between two adjacent active material layer units to form a conductive separation layer. The active material layer unit is a 300μm thick LiNi 0.8 Co 0.15 Al 0.05 O2 ternary material active material layer.

[0077] In the exemplary embodiment, the electrode sheet is a positive electrode sheet, which contains a 20μm aluminum foil current collector, and an active material layer is laminated on two opposite surfaces. The active material layer contains more than two active material layer units, and each active material layer unit is laminated and bonded to the surface of the aluminum foil current collector at intervals; the width of a single active material layer unit is 50μm; the spacing between two adjacent active material layer units is 10μm, and carbon nanotubes are filled between two adjacent active material layer units to form a conductive separation layer. The active material layer unit is a 200μm thick LiNi 0.8 Co 0.15 Al 0.05 O2 ternary material active material layer.

[0078] In the exemplary embodiment, the electrode sheet is a positive electrode sheet, which contains a 20μm copper foil current collector, and an active material layer is laminated on two opposite surfaces. The active material layer contains more than two active material layer units, and each active material layer unit is laminated and bonded on the surface of the copper foil current collector at intervals; the width of a single active material layer unit is 70μm; the spacing between two adjacent active material layer units is 10μm, and a Ketjen black conductive separation layer is filled between two adjacent active material layer units. The active material layer unit is a 200μm thick silicon material active material layer.

[0079] In the exemplary embodiment, the electrode sheet is a positive electrode sheet, which contains a 20μm copper foil current collector, and an active material layer is laminated on two opposite surfaces. The active material layer contains more than two active material layer units, and each active material layer unit is laminated and bonded on the surface of the copper foil current collector at intervals; the width of a single active material layer unit is 100μm; the spacing between two adjacent active material layer units is 20μm, and a Ketjen black conductive separation layer is filled between two adjacent active material layer units. The active material layer unit is a 300μm thick silicon material active material layer.

[0080] In the exemplary embodiment, the electrode sheet is a positive electrode sheet, which contains a 20μm copper foil current collector, and an active material layer is laminated on two opposite surfaces. The active material layer contains more than two active material layer units, and each active material layer unit is laminated and bonded on the surface of the copper foil current collector at intervals; the width of a single active material layer unit is 70μm; the spacing between two adjacent active material layer units is 10μm, and carbon nanotubes are filled between two adjacent active material layer units to form a conductive separation layer. The active material layer unit is a 200μm thick silicon material active material layer.

[0081] In addition, the electrode sheets of the above embodiments can be prepared according to the following method:

[0082] like Figure 5 As shown, the following steps may be included:

[0083] S1, firstly, coating the electrode active layer slurry on at least one surface of the current collector 1 according to a conventional electrode sheet preparation method to obtain a planar electrode,

[0084] S2, scraping the planar electrode into a tunnel structure with equal spacing through a scraping process to form a plurality of active material layer units 21 arranged at intervals;

[0085] S3, filling the trench between two adjacent active material layer units 21 with conductive material to form a conductive separation layer 22, and finally performing subsequent processing to obtain an electrode sheet.

[0086] In a second aspect, the present application also provides a battery. The battery of the present application includes necessary components such as a positive electrode, a negative electrode and a separator, or necessary components such as a positive electrode sheet, a negative electrode sheet and a solid electrolyte layer, and of course other necessary or auxiliary components.

[0087] Among them, at least one of the positive electrode and the negative electrode of the battery is the electrode sheet of the above-mentioned application embodiment.

[0088] In the embodiment, when the positive electrode of the battery is the electrode sheet of the embodiment of the present application, the active material layer unit 21 contained in the electrode sheet of the embodiment of the present application is a positive electrode active material layer unit.

[0089] In the embodiment, when the negative electrode of the battery is the electrode sheet of the embodiment of the present application, the active material layer unit 21 contained in the electrode sheet of the embodiment of the present application is a negative electrode active material layer unit.

[0090] Since the battery of the present application embodiment contains the electrode sheet of the above-mentioned embodiment, the battery of the present application embodiment has high rate capability and cycle performance. When the electrode sheet of the above-mentioned embodiment is a thick electrode sheet, the battery of the present application embodiment also has high energy density.

[0091] In addition, the lithium battery in the embodiment of the present application can be a lithium ion battery or a lithium metal battery, or a sodium ion battery.

[0092] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. An electrode sheet, comprising a current collector and an active material layer arranged on the surface of the current collector, characterized in that: The active material layer includes more than two active material layer units, and each of the active material layer units is arranged on the surface of the current collector at equal intervals from each other; a conductive separation layer is filled between two adjacent active material layer units, and the conductive separation layer is connected to the current collector.

2. The electrode sheet according to claim 1, characterized in that: The active material layer units are arranged on the surface of the current collector at intervals along the length direction of the current collector.

3. The electrode sheet according to claim 1, characterized in that: The active material layer units are arranged on the surface of the current collector at intervals along the width direction of the current collector.

4. The electrode sheet according to claim 1, characterized in that: The conductive separation layer is in a grid structure and surrounds each of the active material layer units.

5. The electrode sheet according to any one of claims 1 to 4, characterized in that: The conductive separation layer includes one or more of the following (1) to (4): (1) The width of the conductive separation layer is 5 to 20 μm; (2) The thickness of the conductive separator layer is 100 to 300 μm; (3) The filling material of the conductive separation layer includes one of carbon black, acetylene black, Ketjen black, carbon nanotubes, graphene, aluminum metal particles, copper metal particles and nickel metal particles; (4) The amount of elastic deformation of the conductive separation layer is greater than the amount of elastic deformation of the active material layer unit.

6. The electrode sheet according to any one of claims 1 to 4, characterized in that: The conductive separator layer contains a porous structure; and / or The conductive separator layer has the same thickness as the active material layer.

7. The electrode sheet according to any one of claims 1 to 4, characterized in that: The current collector has a thickness of 10 to 30 μm; and / or The thickness of the active material layer is 100 to 300 μm; and / or The width of the active material layer unit is 50 to 100 μm.

8. The electrode sheet according to any one of claims 1 to 4, characterized in that: The current collector has two opposite surfaces, and the active material layer and the conductive separator layer are disposed on both surfaces.

9. The electrode sheet according to claim 8, characterized in that: The thickness of each active material layer is 100-200 μm.

10. A battery, characterized in that: The electrode sheet comprises the electrode sheet according to any one of claims 1 to 9.

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