Electrode plate and lithium battery

Abstract

The utility model discloses an electrode plate and a battery. The electrode plate comprises a current collector, an active layer and an adsorption layer, the active layer is arranged on the surface of the current collector; the adsorption layer is arranged on the surface, away from the current collector, of the active layer, the ratio of the thickness of the adsorption layer to the thickness of the active layer ranges from 3: 100 to 1: 5, and a micropore structure is formed in the adsorption layer. On the basis, the microporous structure of the adsorption layer located on the outer layer can quickly store lithium ions enriched on the surface of the electrode in a quick charge or low-temperature high-rate current scene, and meanwhile, the adsorption layer is not easily influenced by gravity and mixed with the active layer, so that the lithium precipitation degree of the electrode plate is relatively low, and the cycle performance and the safety performance of the electrode plate and the lithium battery are relatively excellent.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and particularly to an electrode sheet and a lithium battery. Background Art

[0002] A lithium battery is a battery structure that relies on the movement of lithium ions between the positive electrode and the negative electrode to work, and has advantages such as high energy density, long cycle life, and high working voltage, and is widely used in mobile phones, laptop computers, electric vehicles, and energy storage fields.

[0003] With the growing power battery market, users have higher requirements for the performance of lithium batteries, such as high endurance and fast charging rate. During fast charging, a large number of lithium ions are deintercalated from the positive electrode of the battery and cannot be equally embedded in the negative electrode, resulting in lithium plating. Lithium plating not only reduces the battery performance, but also limits the fast charging capacity of the battery, and may cause catastrophic consequences such as combustion and explosion, seriously affecting the safety of fast charging. Utility Model Content

[0004] Based on this, in view of the above technical problems, it is necessary to provide an electrode sheet and a lithium battery, and the electrode sheet has excellent lithium plating resistance performance.

[0005] Based on the above purpose, this application provides an electrode sheet, including a current collector, an active layer, and an adsorption layer. The active layer is disposed on the surface of the current collector; the adsorption layer is disposed on the surface of the active layer facing away from the current collector, and the ratio of the thickness of the adsorption layer to the thickness of the active layer is between (3:100) and (1:5), and the adsorption layer is formed with a microporous structure.

[0006] In one embodiment, the ratio of the thickness of the adsorption layer to the thickness of the active layer is between (3:100) and (1:10); and / or, the ratio of the specific surface area of the adsorption layer to the specific surface area of the active layer is between (2:1) and (5:1).

[0007] In one embodiment, the thickness of the active layer is between 27 microns and 97 microns; and / or, the thickness of the adsorption layer is between 3 microns and 20 microns.

[0008] In one embodiment, the pore diameter of the microporous structure is between 0.5 microns and 3 microns.

[0009] In one embodiment, the pore diameter of the microporous structure is between 0.5 microns and 1 micron.

[0010] In one embodiment, the porosity of the adsorption layer is between 30% and 45%.

[0011] In one embodiment, in the adsorption layer, the porosity of the adsorption layer gradually increases in the direction away from the surface of the current collector.

[0012] In one embodiment, the adsorption layer is an amorphous carbon layer.

[0013] In one embodiment, the adsorption layer is coated on the surface of the active layer; or,

[0014] The adsorption layer includes a plurality of adsorption sites, and the plurality of adsorption sites are arranged in an array to form an adsorption array layer, and the adsorption array layer is disposed on the surface of the active layer facing away from the current collector.

[0015] For the above purpose, the present application further provides a lithium battery, including a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive electrode sheet and the negative electrode sheet; wherein,

[0016] At least one of the positive electrode sheet and the negative electrode sheet is the electrode sheet described in any one of the above.

[0017] Based on the above description, the active layer of the electrode sheet of the present application is disposed on the surface of the current collector, and the adsorption layer is disposed on the side of the active layer facing away from the current collector. The adsorption layer is formed with a microporous structure. The active layer and the adsorption layer are layered and not mixed. Thus, the microporous structure of the outer adsorption layer can quickly store the lithium ions enriched on the electrode surface in the fast charging or low-temperature high-rate current scenario in its microporous space. At this time, the lithium ions are stored in the microporous structure instead of being on the electrode surface to form lithium deposition and then become dead lithium, which affects the cycle and safety of the battery. The electrode sheet of the present application has better lithium deposition resistance performance; at the same time, the ratio of the thickness of the adsorption layer to the thickness of the active layer is between (3:100) and (1:5). The thickness of the adsorption layer is relatively thin, and the adsorption layer is not easily affected by gravity and mixed with the active layer, thereby affecting the microporous structure on the surface of the electrode sheet and the storage capacity of the adsorption layer. Moreover, the microporous structure formed by the adsorption layer can also block the electrolyte solvent molecules in the separator or the battery space, reducing the reduction decomposition of the solvent molecules by the electrode. Based on this, the degree of lithium deposition of the electrode sheet of the present application is relatively low, the electrode sheet has a high ability to resist the risk of lithium deposition, and the cycle performance and safety performance of the electrode sheet and the lithium battery are both better. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of an electrode sheet provided by an embodiment of the present application;

[0019] Figure 2 It is a schematic structural diagram of a microporous structure of an adsorption layer of an electrode sheet provided by an embodiment of the present application;

[0020] Figure 3 It is a schematic structural diagram of a lithium battery provided by an embodiment of the present application.

[0021] The reference numerals in the embodiments of the present application are described as follows:

[0022] 10. Lithium battery; 100. Electrode sheet; 200. Positive electrode sheet; 300. Negative electrode sheet; 400. Separator; 110. Current collector; 120. Active layer; 130. Adsorption layer; 131. Microporous structure. Specific embodiments

[0023] The following will combine the attached Figure 1 to the attached Figure 3 and embodiments to clearly and completely describe the technical solutions in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present application.

[0024] Referring to "embodiments" herein means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears at various positions 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.

[0025] The following will be described in detail with specific embodiments. It should be noted that the embodiments of the present application can be presented in various forms, and some examples will be described below.

[0026] Lithium batteries or power batteries are prone to lithium plating in fast charging scenarios or low-temperature high-rate current scenarios. In related technologies, amorphous carbon and graphite active materials are often used in combination to improve the low-temperature and rate performance of the electrode structure. However, the electrode scheme using a combination still has a relatively serious lithium plating problem in ultra-low temperature and higher rate scenarios.

[0027] In view of the technical problem that lithium metal plating is likely to occur in the fast charging scenario or the low-temperature high-rate current scenario for lithium batteries or power batteries, the present application provides an electrode sheet 100 and a lithium battery 10. An adsorption layer 130 is provided on the surfaces of the current collector 110 and the active layer 120. The adsorption layer 130 is formed with a microporous structure 131. The microporous structure 131 of the adsorption layer 130 located outside the active layer 120 can quickly store the lithium ions enriched on the electrode surface in the fast charging or low-temperature high-rate current scenario in the microporous space. At this time, the lithium ions are stored in the microporous structure 131 instead of being located on the electrode surface and forming lithium metal plating, which will turn into dead lithium and affect the cycle and safety of the battery. The electrode sheet 100 has excellent lithium metal plating resistance performance, and the lithium battery 10 or the power battery has excellent cycle and safety performance.

[0028] Specifically, please refer to Figure 1 and Figure 2 , Figure 1 which is a schematic structural diagram of the electrode sheet 100 provided by an embodiment of the present application. Figure 2 which is a schematic structural diagram of the microporous structure 131 of the adsorption layer 130 of the electrode sheet 100 provided by an embodiment of the present application. The electrode sheet 100 includes a current collector 110, an active layer 120, and an adsorption layer 130. The active layer 120 is disposed on the surface of the current collector 110, and the adsorption layer 130 is disposed on the surface of the active layer 120 facing away from the current collector 110. The ratio of the thickness of the adsorption layer 130 to the thickness of the active layer 120 is between (3:100) and (1:5), and the adsorption layer 130 is formed with a microporous structure 131.

[0029] It can be understood that the current collector 110 refers to a structure or component that collects current. The current collector 110 can be, but is not limited to, a metal foil, such as a copper foil or an aluminum foil; the current collector 110 can also generally refer to a tab. The main function of the current collector 110 is to collect the current generated by the battery active material so as to form a larger current for external output. Among them, the internal resistance of the current collector 110 is small, and the current collector 110 is in full contact with the active material in the active layer 120, so that the current performance output by the current collector 110 is better.

[0030] It can be understood that the active layer 120 is an electrode active layer. An active material capable of participating in an electrochemical reaction is provided in the active layer 120. Among them, the active layer 120 can be a positive electrode active layer. At this time, the active material in the active layer 120 is usually lithium iron phosphate, lithium manganese iron phosphate, nickel cobalt manganese ternary, and mixtures of the above substances, etc. The active layer 120 can also be a negative electrode active layer, and the active layer 120 is a graphite layer. At this time, the active material in the active layer 120 is usually artificial graphite, natural graphite, a mixture of graphite and silicon, etc. Among them, the active layer 120 can also include structures such as a conductive agent, a binder, and a dispersant. For example, in some embodiments, the active layer 120 can include 80% to 97% of the active material, 1% to 10% of the conductive agent, 1% to 5% of the binder, and 1% to 5% of the dispersant. Further, the active layer 120 can include 90% of the active material, 6% of the conductive agent, 2% of the binder, and 2% of the dispersant. Further, the active layer 120 can include 94% of the active material, 4% of the conductive agent, 1% of the binder, and 1% of the dispersant. Further, the active layer 120 can include 85% of the active material, 7% of the conductive agent, 5% of the binder, and 3% of the dispersant.

[0031] It can be understood that the adsorption layer 130 is a conductive layer structure with a microporous structure 131. In some embodiments, the adsorption layer 130 is an amorphous carbon layer. Among them, amorphous carbon, also known as transitional carbon, is a large category in the allotropes of carbon. Amorphous carbon refers to those carbon materials with a very low degree of graphitization crystallization, similar to an amorphous state (or no fixed shape and periodic structural rules), such as soft carbon, hard carbon, carbon black, etc. The adsorption layer 130 of the present application is an amorphous carbon layer. On the one hand, amorphous carbon has electrical conductivity. On the other hand, the amorphous carbon layer has excellent microporous adsorption performance. Therefore, the structure of the adsorption layer 130 of the present application is simple and the adsorption effect is better.

[0032] It can be understood that the microporous structure 131 formed by the adsorption layer 130, such as an amorphous carbon layer, can adsorb the surrounding lithium ions and store the lithium ions. The lithium ions are not easily enriched on the surface of the lithium battery 10 and combine with electrons, resulting in the phenomenon of lithium deposition. Among them, as Figure 2 shown, the microporous structure 131 in the adsorption layer 130 can be a triangular microporous structure, a quadrilateral microporous structure, or a microporous structure of other shapes. And, the shapes of the multiple microporous structures 131 in the adsorption layer 130 can be the same or different, and the embodiments of the present application do not limit this.

[0033] It is understandable that the ratio of the thickness of the adsorption layer 130 to the thickness of the active layer 120 in this application is between (3:100) and (1:5). The thickness here refers to the dimension of the adsorption layer 130 and the active layer 120 along the direction from the current collector 110 to the adsorption layer 130. Among them, further, the ratio of the thickness of the adsorption layer 130 to the thickness of the active layer 120 is between (3:100) and (1:10). Among them, even further, the ratio of the thickness of the adsorption layer 130 to the thickness of the active layer 120 is between (3:100) and (1:20). Among them, in some embodiments, the ratio of the thickness of the adsorption layer 130 to the thickness of the active layer 120 is (3:100), (1:20), (2:25), (1:10), (3:25), (3:20), (9:50), or (1:5).

[0034] When the ratio of the thickness of the adsorption layer 130 to the thickness of the active layer 120 in this application is between (3:100) and (1:5), the thickness of the adsorption layer 130 is relatively thin, and the substances in the adsorption layer 130 are not easily precipitated into the active layer 120, and the adsorption layer 130 can better store lithium ions. It should be noted that in the numerical range of this application, the endpoint values are included without special instructions.

[0035] In the electrode sheet 100 of the embodiment of this application, the active layer 120 is disposed on the surface of the current collector 110, the adsorption layer 130 is disposed on the side of the active layer 120 facing away from the current collector 110, the adsorption layer 130 is formed with a microporous structure 131, and the active layer 120 and the adsorption layer 130 are disposed in layers without being mixed. Thus, the microporous structure 131 of the adsorption layer 130 located on the outer layer can quickly store the lithium ions enriched on the electrode surface in the fast charging or low-temperature high-rate current scenario in its microporous space. At this time, the lithium ions are stored in the microporous structure 131 instead of forming lithium deposition on the electrode surface and then becoming dead lithium, which affects the cycle and safety of the battery. At the same time, the ratio of the thickness of the adsorption layer 130 to the thickness of the active layer 120 is between 3% and 20%. The thickness of the adsorption layer 130 is relatively thin, and the adsorption layer 130 is not easily affected by gravity and mixed with the active layer 120, which affects the microporous structure 131 on the surface of the electrode sheet 100, and further affects the storage capacity of the adsorption layer 130. Moreover, the microporous structure 131 formed by the adsorption layer 130 can also block the electrolyte solvent molecules in the active layer 120, reducing the reduction decomposition of the solvent molecules by the electrode. Based on this, the degree of lithium deposition of the electrode sheet 100 of this application is relatively low, the electrode sheet 100 has a high ability to resist the risk of lithium deposition, and the cycle performance and safety performance of the electrode sheet 100 and the lithium battery 10 are both better.

[0036] In some embodiments, the sum of the thickness of the active layer 120 and the thickness of the adsorption layer 130 is between 30 microns and 100 microns. In some embodiments, the thickness of the active layer 120 is between 27 microns and 97 microns, for example, the thickness of the active layer 120 may be 27 microns, 40 microns, 60 microns, 80 microns, 90 microns, 97 microns, etc. In other embodiments, the thickness of the adsorption layer 130 is between 3 microns and 20 microns, for example, the thickness of the adsorption layer 130 is 3 microns, 5 microns, 9 microns, 12 microns, 15 microns, 18 microns and 20 microns.

[0037] In some embodiments, the thickness of the active layer 120 may be 30 microns, and the thickness of the adsorption layer 130 may be 3 microns. In other embodiments, the thickness of the active layer 120 may be 90 microns, and the thickness of the adsorption layer 130 may be 5 microns. The specific thickness of the active layer 120 and the adsorption layer 130 is not limited in the embodiments of the present application.

[0038] In some embodiments, the ratio of the coating area of ​​the active layer 120 to the coating area of ​​the adsorption layer 130 is generally 1:1, and the projected areas of the active layer 120 and the adsorption layer 130 on the current collector 110 are equal.

[0039] In some embodiments, please refer to Figure 2 , the pore size of the microporous structure 131 of the embodiment of the present application is between 0.5 microns and 3 microns. For example, the pore size of the microporous structure 131 can be 0.5 microns, 1 micron, 1.5 microns, 2 microns, 2.5 microns or 3 microns. Further, the pore size of the microporous structure 131 of the embodiment of the present application is between 0.5 microns and 1 micron, for example, the pore size of the microporous structure 131 can be 0.5 microns, 0.7 microns, 0.9 microns or 1 micron. At this time, the opening of the microporous structure 131 of the embodiment of the present application is neither too large nor too small. If the pore size of the microporous structure 131 is too small, for example, the pore size of the microporous structure 131 is 0.01 microns, the microporous structure 131 is too small and is not easy to become a lithium storage space; if the pore size of the microporous structure 131 is too large, for example, the pore size of the microporous structure 131 is 50 microns, the microporous structure 131 is too large, and the lithium ions stored in the microporous structure 131 and the electrolyte solvent molecules in the separator 400 or the lithium battery 10 space are easy to seep out of the microporous structure 131 and leave the microporous structure 131. In the embodiment of the present application, the pore size of the microporous structure 131 is between 0.5 microns and 3 microns, and the pore size of the microporous structure 131 is neither too large nor too small, and the microporous structure 131 can store lithium ions well; at the same time, the lithium ions, the electrolyte solvent molecules in the separator 400 or the lithium battery 10 space are not easy to leave the microporous structure 131, so that the electrode sheet 100 of the embodiment of the present application has better performance.

[0040] Among them, in some embodiments, the porosity of the adsorption layer 130 is between 30% and 45%. For example, the porosity of the adsorption layer 130 is 30%, 35%, 40% or 45%. When the porosity of the adsorption layer 130 is between 30% and 45%, the number of microporous structures 131 in the adsorption layer 130 is relatively large, and the adsorption layer 130 has a better storage effect on lithium ions.

[0041] Among them, in some embodiments, along the direction away from the surface of the current collector 110, the porosity of the adsorption layer 130 gradually increases in the adsorption layer 130. That is to say, the porosity of the adsorption layer 130 in the region close to the active layer 120 is smaller than the porosity of the adsorption layer 130 in the region far from the active layer 120. This makes the porosity of the side of the adsorption layer 130 facing away from the active layer 120 larger. The adsorption layer 130 with a larger porosity has a larger microporous space, and the microporous structure 131 of the adsorption layer 130 is more likely to store lithium ions, so that the performance of the adsorption layer 130 in storing lithium ions is better.

[0042] Among them, in some embodiments, the specific surface area of the adsorption layer 130 is larger than the specific surface area of the active layer 120. Further, the ratio of the specific surface area of the adsorption layer 130 to the specific surface area of the active layer 120 is between (2:1) and (5:1). For example, the ratio of the specific surface area of the adsorption layer 130 to the specific surface area of the active layer 120 is (2:1), (2.5:1), (3:1), (3.5:1), (4:1), (4.5:1) or (5:1). Among them, the specific surface area refers to the total area per unit mass of the material. Among them, in some embodiments, the specific surface area of the adsorption layer 130 is between 3 m² / g and 6 m² / g. For example, the specific surface area of the adsorption layer 130 is 3 m² / g, 4 m² / g, 5 m² / g or 6 m² / g. In some other embodiments, the specific surface area of the active layer 120 is between 1.2 m² / g and 1.5 m² / g. For example, the specific surface area of the active layer 120 is 1.2 m² / g, 1.3 m² / g, 1.4 m² / g, 1.5 m² / g.

[0043] In the embodiment of the present application, the adsorption layer 130 has a larger specific surface area compared with the active layer 120. The adsorption layer 130 with a larger specific surface area is more likely to contact the lithium ions enriched on the surface of the electrode in the fast charging or low-temperature high-rate current scenario, so that the adsorption layer 130 can store the lithium ions in its microporous structure 131 more quickly.

[0044] Among them, in some embodiments, the adsorption layer 130 of the electrode sheet 100 in the embodiment of the present application can be disposed on the surface of the active layer 120 and coated on the surface of the active layer 120. The adsorption layer 130 can completely cover the surface of the active layer 120, and the adsorption layer 130 has a large adsorption area.

[0045] Of course, in some other embodiments, the adsorption layer 130 includes a plurality of adsorption sites, which are arranged in an array to form an adsorption array layer, and the adsorption array layer is disposed on the side of the active layer 120 facing away from the current collector 110. In the embodiments of the present application, the adsorption layer 130 is an adsorption array layer and is disposed on the surface of the active layer 120. The plurality of adsorption sites do not need to cover the entire surface of the active layer 120, saving the material cost of the adsorption layer 130.

[0046] Among them, in some embodiments, the active layer 120 can be formed on the current collector 110 by extrusion coating or transfer coating. In some embodiments, when the thickness of the adsorption layer 130 is small, for example, when the adsorption layer 130 is 3 to 5 micrometers, the adsorption layer 130 can be formed on the surface of the active layer 120 by spraying; when the thickness of the adsorption layer 130 is large, for example, when the adsorption layer 130 is 6 to 20 micrometers (6 micrometers, 8 micrometers, 10 micrometers, 15 micrometers or 20 micrometers), the adsorption layer 130 and the active layer 120 can be formed on the current collector 110 synchronously by a double-layer extrusion coating method.

[0047] Based on the structure of the above electrode sheet 100, the active layer 120 and the adsorption layer 130 are arranged in layers. The microporous structure 131 of the adsorption layer 130 located on the outer layer can quickly store lithium ions, thereby reducing the degree of lithium deposition of the electrode sheet 100 of the present application; at the same time, the present application limits parameters such as the ratio of the thickness of the adsorption layer 130 to the thickness of the active layer 120, the pore diameter of the microporous structure 131, and the porosity of the adsorption layer 130, so that the performance of the adsorption layer 130 for storing lithium ions is better. The degree of lithium deposition of the electrode sheet 100 of the present application is reduced, and the cycle performance and safety performance of the electrode sheet 100 and the lithium battery 10 are both better.

[0048] Based on the structure of the above electrode sheet 100, please refer to Figure 3 , Figure 3 which is a schematic structural diagram of a lithium battery 10 provided by an embodiment of the present application. The lithium battery 10 includes a positive electrode sheet 200, a negative electrode sheet 300, and a separator 400 disposed between the positive electrode sheet 200 and the negative electrode sheet 300. Among them, at least one of the positive electrode sheet 200 and the negative electrode sheet 300 can be the electrode sheet 100 in any of the above embodiments.

[0049] For example, in some embodiments, the negative electrode sheet 300 of the lithium battery 10 may include the current collector 110, the active layer 120, and the adsorption layer 130 of the foregoing embodiments; the active layer 120 is disposed on the surface of the current collector 110; the adsorption layer 130 is disposed on the side of the active layer 120 facing away from the current collector 110, and the ratio of the thickness of the adsorption layer 130 to the thickness of the active layer 120 is between (3:100) and (1:5), and the adsorption layer 130 is formed with a microporous structure 131. Of course, in other embodiments, the positive electrode sheet 200 of the lithium battery 10 may also include the current collector 110, the active layer 120, and the adsorption layer 130 of the foregoing embodiments. Details are not described herein.

[0050] It can be understood that the lithium battery 10 may further include other structures, such as but not limited to, the lithium battery 10 may further include a housing, a protection circuit board, etc. Among them, the housing is used for the encapsulation of the lithium battery 10, and the housing may include structures such as an aluminum shell, a cover plate, a tab, and an insulating sheet. The protection circuit board is used to protect the lithium battery 10 to prevent the lithium battery 10 from overcharging, over-discharging, over-current, etc.

[0051] In the lithium battery 10 of the embodiment of the present application, at least one of the positive electrode sheet 200 and the negative electrode sheet 300 of the lithium battery 10 may layer the active layer 120 and the adsorption layer 130, so that the microporous structure 131 of the adsorption layer 130 located in the outer layer can quickly store lithium ions. Furthermore, the lithium battery 10 of the embodiment of the present application has better cycle performance and safety performance.

[0052] It should be understood that in the description of the present application, terms such as "first" and "second" are only used to distinguish similar objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features.

[0053] It can be understood that those skilled in the art can combine various implementation manners in the above embodiments under the teaching of the above embodiments to obtain technical solutions of various implementation manners. The above are only the preferred embodiments of the present application, and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0054] The above provides a detailed introduction to the thermal runaway detection device provided by the present application. Specific examples are used herein to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the present application. At the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. An electrode sheet, characterized in that: The invention comprises a current collector, an active layer and an adsorption layer, wherein the active layer is arranged on the surface of the current collector, and the adsorption layer is arranged on the surface of the active layer away from the current collector. The ratio of the thickness of the adsorption layer to the thickness of the active layer is between (3:100) and (1:5), and the adsorption layer forms a microporous structure.

2. The electrode sheet according to claim 1, characterized in that: The ratio of the thickness of the adsorption layer to the thickness of the active layer is between (3:100) and (1:10); and / or the ratio of the specific surface area of ​​the adsorption layer to the specific surface area of ​​the active layer is between (2:1) and (5:1).

3. The electrode sheet according to claim 1, characterized in that: The thickness of the active layer is between 27 micrometers and 97 micrometers; and / or the thickness of the adsorption layer is between 3 micrometers and 20 micrometers.

4. The electrode sheet according to claim 1, characterized in that: The pore size of the microporous structure is between 0.5 micrometers and 3 micrometers.

5. The electrode sheet according to claim 4, characterized in that: The pore size of the microporous structure is between 0.5 micrometer and 1 micrometer.

6. The electrode sheet according to claim 1, characterized in that: The porosity of the adsorption layer is between 30% and 45%.

7. The electrode sheet according to claim 6, characterized in that: In the adsorption layer, the porosity of the adsorption layer gradually increases along a direction away from the surface of the current collector.

8. The electrode sheet according to any one of claims 1 to 7, characterized in that: The adsorption layer is an amorphous carbon layer.

9. The electrode sheet according to any one of claims 1 to 7, characterized in that: The adsorption layer is coated on the surface of the active layer; or, The adsorption layer includes a plurality of adsorption points, which are arranged in an array to form an adsorption array layer. The adsorption array layer is arranged on a surface of the active layer away from the current collector.

10. A lithium battery, characterized in that: It includes a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive electrode sheet and the negative electrode sheet; wherein, At least one of the positive electrode sheet and the negative electrode sheet is the electrode sheet according to any one of claims 1 to 9.

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