Coating drying method, device and sodium-ion battery electrode pole piece

Abstract

This invention provides a coating drying method, equipment, and sodium-ion battery electrode sheet, relating to the field of sodium-ion battery electrode sheet coating drying technology. The method includes: the coated wet electrode sheet undergoes at least three functionally independent drying stages sequentially; the first stage uses a drying medium at 70℃~90℃ and a wind speed of 5~15m / s to perform directional impact drying on the surface of the wet electrode sheet, forming a porous framework structure on the wet coating surface; the second stage uses a drying medium at 100℃~130℃ and a wind speed of 2~5m / s to perform convective drying on the electrode sheet; and the third stage uses a drying medium at 130℃~160℃, a wind speed of 0.5~2m / s, and a dew point temperature ≤-20℃ to perform cyclic drying on the electrode sheet. Through the synergistic effect of these three functionally independent and parameter-differentiated drying stages, directional, gentle, and thorough drying of the sodium-ion battery electrode coating is achieved, effectively suppressing defects such as coating surface skinning, binder migration, microcrack formation, and excessive residual moisture, significantly improving the cycle life and electrochemical performance of the sodium-ion battery.

Description

Technical Field

[0001] This invention relates to the field of coating and drying technology for sodium-ion battery electrode sheets, and more specifically, to a coating and drying method, equipment, and sodium-ion battery electrode sheet. Background Technology

[0002] In the manufacturing process of sodium-ion battery electrodes, coating and drying are key steps that determine the electrode's microstructure, mechanical properties, and final electrochemical performance. The active materials used in sodium-ion batteries (such as layered oxides, Prussian blue-based cathodes, and hard carbon anodes) differ significantly from those in lithium-ion batteries in their physicochemical properties (such as density, specific surface area, surface functional groups, and moisture sensitivity). This leads to differences in the solvent evaporation kinetics, binder migration behavior, and drying stress of sodium-ion battery slurries compared to lithium-ion battery slurries.

[0003] Traditional lithium battery electrodes generally employ single-stage or simple multi-stage hot air drying, primarily aimed at rapidly removing solvents. However, when directly applied to the drying of sodium battery electrodes, the following compatibility issues often arise: First: Coating surface crusting and internal structural damage: Rapid temperature rise during the initial drying stage causes a dense, hard shell to quickly form on the coating surface. The internal solvent rapidly vaporizes, generating vapor pressure, which leads to microcracks in the electrode and damages the conductive network. Second: Uneven binder migration and distribution: During the drying process, the solvent migrates towards the evaporation surface under capillary force, causing the binder to accumulate on the surface, resulting in binder depletion at the bottom of the electrode and a decrease in coating cohesion and adhesion to the current collector. Third: Incomplete removal of residual solvent / moisture: Traditional processes struggle to reduce residual solvent / moisture levels in the electrode while maintaining production efficiency. Residual solvents are prone to side reactions with sodium-based active materials, deteriorating battery performance.

[0004] Therefore, there is an urgent need to propose a coating and drying method, equipment, and sodium-ion battery electrode sheet. Summary of the Invention

[0005] In order to overcome the above-mentioned technical problems, the present invention aims to provide a coating and drying method, equipment and sodium-ion battery electrode sheet.

[0006] The objective of this invention can be achieved through the following technical solutions: A coating and drying method includes sequentially passing the coated wet electrode sheet through at least three functionally independent drying stages: The first stage uses a drying medium with a temperature of 70℃~90℃ and a wind speed of 5~15m / s to perform directional impact drying on the surface of the wet electrode to form a porous skeleton structure on the surface of the wet coating. The second stage uses a drying medium with a temperature of 100℃~130℃ and a wind speed of 2~5m / s to convectively dry the electrode sheets; The third stage involves circulating drying of the electrode sheets using a drying medium with a temperature of 130℃~160℃, a wind speed of 0.5~2m / s, and a dew point temperature ≤-20℃.

[0007] As a further aspect of the present invention: the airflow direction of the drying medium in the first stage is perpendicular to the electrode surface or forms an acute angle of ≤30° with the electrode travel direction.

[0008] As a further aspect of the present invention: the airflow direction of the drying medium in the second stage is parallel to the electrode.

[0009] As a further aspect of the present invention: during the entire drying process, the tension of the electrode is controlled to remain constant, with a tension value range of 20~100N / m.

[0010] As a further aspect of the present invention: in the third stage, dehumidified dry air or nitrogen is introduced as a drying medium.

[0011] A coating and drying apparatus for implementing any of the coating and drying methods described above includes a first drying unit, a second drying unit, and a third drying unit arranged sequentially along the electrode travel direction. The first drying unit includes an air outlet for generating high-speed directional impact air, the air outlet facing the electrode surface; the second drying unit includes an air box for generating uniform parallel convection air; the third drying unit includes a low-speed circulating air system, the circulating air system being connected to a dehumidifier unit.

[0012] As a further aspect of the present invention: the air outlet of the first drying unit is a nozzle, and the air outlet direction of the nozzle is perpendicular to the surface of the electrode or forms an acute angle of ≤30° with the direction of travel of the electrode; the airflow direction generated by the air box of the second drying unit is parallel to the electrode.

[0013] As a further aspect of the present invention, it also includes a tension control system, which is used to control the electrode tension to 20~100N / m on the electrode transport path.

[0014] As a further aspect of the present invention, an isolation air curtain is provided between adjacent drying units to achieve physical isolation.

[0015] A sodium-ion battery electrode sheet is prepared by any of the coating and drying methods described above.

[0016] The beneficial effects of this invention include, but are not limited to: In the first stage, a drying medium at a temperature of 70℃~90℃ and a wind speed of 5~15m / s is used to perform directional impact drying on the surface of the wet electrode sheet. This rapidly evaporates the solvent on the surface of the wet coating, forming a porous framework structure that locks in the macroscopic morphology of the coating and prevents the binder from migrating to the evaporation surface with the solvent. In the second stage, a drying medium at a temperature of 100℃~130℃ and a wind speed of 2~5m / s is used to perform convective drying on the electrode sheet, removing the main solvent inside the coating in a gentle and uniform manner, avoiding a sudden increase in internal vapor pressure that could lead to microcracks. In the third stage, a drying medium at a temperature of 130℃~90℃ and a wind speed of 2~5m / s is used to perform convective drying on the electrode sheet. The electrode is cyclically dried using a drying medium ranging from 100℃ to 160℃, with a wind speed of 0.5 to 2 m / s and a dew point temperature ≤ -20℃. The low dew point drying medium creates a strong solvent concentration gradient to deeply remove residual trace solvents. At the same time, the high-temperature environment promotes the relaxation of micro-stress in the coating. Through the synergistic effect of the above three functionally independent and parameter-differentiated drying stages, the method of this application achieves directional, gentle, and thorough drying of the sodium-ion battery electrode coating, effectively suppressing defects such as coating surface skinning, binder migration, microcrack generation, and excessive residual moisture, and significantly improving the cycle life and electrochemical performance of the sodium-ion battery. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the coating and drying method according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a coating and drying apparatus according to an embodiment of the present invention.

[0018] Explanation of reference numerals in the attached drawings: 1. First drying unit; 2. Second drying unit; 3. Third drying unit; 31. Low-speed circulating air system; 32. Dehumidifier unit; 4. Isolation air curtain; 5. Conveying device. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, specific embodiments of this application are described clearly and completely below with reference to the accompanying drawings. It should be understood that the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments described in this application without creative effort will fall within the scope of protection of this application.

[0020] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application is for the purpose of describing specific embodiments only and is not intended to limit this application; the terms "comprising," "including," "having," "containing," "comprise," etc., in the specification, claims, and accompanying drawings of this application are open-ended terms, indicating that a method comprises one or more steps, or an apparatus comprises one or more elements, but do not exclude the inclusion of other steps or elements. The terms "first," "second," etc., in the specification, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or primary / secondary relationship. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0021] In the description of this application, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0023] In the manufacturing process of sodium-ion battery electrodes, the surface coating of the wet electrode sheet after coating contains a large amount of solvent (water in aqueous slurries, and organic solvents such as NMP in organic slurries), and the coating is in an uncured state. See also Figure 1An embodiment of the present invention provides a coating drying method comprising: the coated wet electrode sheet sequentially passing through at least three functionally independent drying stages: the first stage uses a drying medium with a temperature of 70℃~90℃ and a wind speed of 5~15m / s to perform directional impact drying on the surface of the wet electrode sheet, so as to form a porous skeleton structure on the surface of the wet coating; the second stage uses a drying medium with a temperature of 100℃~130℃ and a wind speed of 2~5m / s to perform convective drying on the electrode sheet; and the third stage uses a drying medium with a temperature of 130℃~160℃, a wind speed of 0.5~2m / s and a dew point temperature ≤-20℃ to perform cyclic drying on the electrode sheet.

[0024] In the first drying stage, specifically, when a drying medium with a temperature of 70℃~90℃ and a wind speed of 5~15m / s is used to directionally impact the surface of the wet electrode, the drying medium contacts the coating surface with a high convective heat transfer coefficient, causing the solvent on the coating surface to evaporate rapidly. Since the temperature is controlled in the medium-low temperature range of 70℃~90℃ in this stage, it avoids the rapid formation of a dense hard shell on the coating surface due to excessive temperature. At the same time, the high wind speed of 5~15m / s enhances the mass transfer rate of the surface solvent, allowing the surface solvent to be removed in a short time (about 10 seconds), thereby forming a porous skeleton structure on the coating surface. On the one hand, this locks in the macroscopic morphology of the coating, preventing deformation of the coating due to internal solvent migration during subsequent drying. On the other hand, this porous skeleton structure forms a physical barrier on the coating surface, effectively preventing the binder inside the slurry from migrating to the evaporation surface with the solvent, thus maintaining the original uniform distribution of the binder in the coating thickness direction. The amount of solvent removed in this stage accounts for 20%~35% of the total amount, laying the foundation for the main solvent removal in the subsequent stage.

[0025] For the second drying stage, specifically, after the surface shaping in the first stage, a stable porous framework structure has been formed on the coating surface. At this point, the main solvent removal stage begins. A drying medium with a temperature of 100℃~130℃ and a wind speed of 2~5m / s is used to dry the electrode in a convection manner. Compared to the first stage, the temperature in this stage is increased to 100℃~130℃, providing a higher heat input to promote the evaporation of the main solvent inside the coating. At the same time, the wind speed is reduced to 2~5m / s, using a gentle parallel convection method, which allows heat to be transferred to the interior of the coating more evenly. The solvent diffuses from the interior of the coating to the surface and evaporates at a relatively slow rate. This slow-release drying strategy effectively avoids the phenomenon of a sudden increase in vapor pressure caused by rapid vaporization of the solvent inside the coating, thereby preventing micro-cracks from appearing on the electrode and protecting the integrity of the conductive network structure of the coating. The amount of solvent removed in this stage accounts for 50%~65% of the total amount, undertaking the task of removing the vast majority of the solvent.

[0026] For the third drying stage, specifically, after the first two stages of drying, trace amounts of solvent or moisture still remain in the electrode. For sodium-ion battery electrodes, the residual moisture content needs to be controlled at a low level to avoid side reactions between moisture and sodium-ion battery active materials. The third stage uses a drying medium with a temperature of 130℃~160℃, an air velocity of 0.5~2m / s, and a dew point temperature ≤-20℃ for cyclic drying. The higher temperature (130℃~160℃) provides sufficient energy for the removal of residual trace solvents; the lower air velocity (0.5~2m / s) reduces the drying time. The mechanical disturbance of the medium on the electrode surface, while prolonging the contact time between the drying medium and the electrode, is conducive to the complete removal of trace solvents. The low dew point drying medium with a dew point temperature of ≤-20℃ creates a strong solvent concentration gradient, so that even if there are only trace solvents inside the coating, they can continue to diffuse into the drying medium and be carried away under the drive of the concentration gradient. In addition, the high temperature environment at this stage helps the electrode coating to achieve micro-stress relaxation and improve the toughness of the coating. After this stage of deep drying, the final residual solvent / moisture content of the electrode can reach the target value (usually <200ppm).

[0027] In this embodiment, the first stage uses a drying medium at a temperature of 70℃~90℃ and a wind speed of 5~15m / s to perform directional impact drying on the surface of the wet electrode. The solvent on the surface of the wet coating evaporates rapidly, forming a porous framework structure on the coating surface, locking the macroscopic morphology of the coating and preventing the binder from migrating to the evaporation surface with the solvent. The second stage uses a drying medium at a temperature of 100℃~130℃ and a wind speed of 2~5m / s to perform convection drying on the electrode, removing the main solvent inside the coating in a gentle and uniform manner, avoiding the formation of microcracks due to a sudden increase in internal vapor pressure. The third stage uses a drying medium at a temperature of 130℃~160℃ to perform convective drying on the electrode. The electrode is cyclically dried using a drying medium with a temperature of ℃, a wind speed of 0.5~2m / s, and a dew point temperature ≤-20℃. The low dew point drying medium creates a strong solvent concentration gradient to deeply remove residual trace solvents. At the same time, the high temperature environment promotes the relaxation of micro-stress in the coating. Through the synergistic effect of the above three functionally independent and parameter-differentiated drying stages, the method of this application achieves directional, gentle, and thorough drying of the sodium-ion battery electrode coating, effectively suppressing defects such as coating surface skinning, binder migration, microcrack generation, and excessive residual moisture, and significantly improving the cycle life and electrochemical performance of sodium-ion batteries.

[0028] Optionally, the airflow direction of the drying medium in the first stage is perpendicular to the electrode surface or forms an acute angle of ≤30° with the electrode travel direction.

[0029] join Figure 1In this embodiment, when the airflow direction is perpendicular to the electrode surface, the drying medium impacts the electrode surface directly, resulting in high heat transfer efficiency. This allows for rapid heating and solvent evaporation of the coating surface in a short time, facilitating the rapid formation of a porous framework structure. When the airflow direction forms an acute angle ≤30° with the electrode's travel direction, the drying medium, while impacting the electrode surface, also possesses a velocity component along the electrode's travel direction. This velocity component is aligned with or at a small angle to the electrode's travel direction, reducing excessive impact on the electrode surface and mitigating the risk of mechanical disturbance to the uncured coating, while still maintaining high convective heat transfer efficiency. Both airflow directions are suitable for the first-stage rapid surface setting process, and those skilled in the art can choose the appropriate direction based on actual process requirements.

[0030] See Figure 1 Optionally, the airflow direction of the drying medium in the second stage is parallel to the electrode. In this embodiment, during the slow-release drying process of the main solvent in the second stage, the airflow direction of the drying medium is set to be parallel to the electrode, so that the drying medium flows along the surface of the electrode and forms a uniform convective drying environment. The parallel airflow direction avoids direct impact on the coating and reduces the uneven drying phenomenon on the coating surface caused by airflow impact. At the same time, the parallel airflow makes the heat transfer and solvent removal process more uniform and gentle, which is conducive to the solvent inside the coating diffuses and evaporates outward at a slow rate, further reducing the risk of microcracks caused by a sudden increase in internal vapor pressure.

[0031] Optionally, throughout the drying process, the tension of the electrode is kept constant, with a tension value ranging from 20 to 100 N / m. In this embodiment, the electrode tends to shrink during the drying process due to solvent removal. Constant tension can suppress the lateral shrinkage deformation of the electrode and reduce cracks in the coating caused by shrinkage stress. The tension control system can be implemented using a tension sensor in conjunction with a servo motor or magnetic powder brake, as is available in the prior art. By detecting the electrode tension in real time and feeding back to adjust the speed or braking torque of the drive roller, constant tension control is achieved.

[0032] See Figure 1 Optionally, in the third stage, dehumidified dry air or nitrogen is introduced as the drying medium to ensure that the dew point temperature of the drying medium reaches ≤-20℃. The dehumidification process can be achieved by existing technologies such as rotary dehumidification or adsorption dehumidification.

[0033] See Figures 1-2Another embodiment of the present invention provides a coating drying apparatus for implementing any of the coating drying methods described above, comprising a first drying unit 1, a second drying unit 2, and a third drying unit 3 arranged sequentially along the electrode traveling direction; the first drying unit 1 includes an air outlet for generating high-speed directional impact air, the air outlet facing the electrode surface; the second drying unit 2 includes a wind box for generating uniform parallel convection air; the third drying unit 3 includes a low-speed circulating air system 31, the circulating air system being connected to a dehumidifier unit 32.

[0034] In this embodiment, the first drying unit 1 is used to implement the first stage of the rapid surface shaping process in the coating drying method. Its air outlet can be a hot air knife or a slit nozzle. The hot air knife sprays the heated drying medium out at high speed and in a directional manner through a narrow slit, forming a concentrated impact airflow. The slit nozzle, through a precision-machined slit structure, straightens the airflow into a uniform high-speed jet. The above-mentioned air outlet structures are all mature existing technologies in the field and can be selected according to process requirements. The air outlet is arranged facing the electrode surface, so that the high-speed drying medium can directly impact the electrode coating surface to achieve rapid surface shaping.

[0035] The second drying unit 2 is used to implement the second stage of the coating drying method, namely the slow-release drying process of the main solvent. The air outlet of the air box can be set as a narrow slit extending along the width direction of the electrode or an array of air outlets to ensure the drying uniformity across the entire width of the electrode. The third drying unit 3 is used to implement the third stage of the coating drying method. The low-speed circulating air system 31 can be implemented using a circulating fan and circulating duct in the prior art. The circulating duct sends the drying medium out from the air outlet of the third drying unit 3, flows over the surface of the electrode, and is then recovered by the return air outlet. After being processed by the dehumidifier unit 32, it is sent back into the circulating duct by the circulating fan, forming a closed loop. The dehumidifier unit 32 can be a rotary dehumidifier in the prior art. The first drying unit 1, the second drying unit 2, and the third drying unit 3 are arranged sequentially along the electrode traveling direction. The electrode passes through each drying unit sequentially via a transfer roller group or a drive belt, completing the three-stage continuous drying process.

[0036] See Figure 1 and Figure 2 Optionally, the air outlet of the first drying unit 1 is a nozzle, and the air outlet direction of the nozzle is perpendicular to the surface of the electrode or at an acute angle of ≤30° with the direction of travel of the electrode, so as to achieve the directional blowing requirements of the first stage; the airflow direction generated by the air box of the second drying unit 2 is parallel to the electrode, so as to meet the airflow requirements of the second stage.

[0037] Optionally, the coating and drying equipment also includes a tension control system for controlling the electrode tension to 20~100 N / m (based on the electrode width) on the electrode transport path. The coating and drying equipment also includes a conveying device 5 for transporting the electrode. The first drying unit 1, the second drying unit 2, and the third drying unit 3 are arranged sequentially along the transport path of the conveying device 5. The electrode is driven by the conveying device 5 to pass through the first drying unit 1, the second drying unit 2, and the third drying unit 3 in sequence. The conveying device 5 can adopt a roller-to-roll transport system or a conveyor belt transport system as known in the art.

[0038] In this embodiment, the tension control system is configured in conjunction with the conveying device 5. The tension control system can be a closed-loop tension control system in the art, such as a magnetic powder brake in conjunction with a tension sensor, a servo motor in conjunction with a floating roller, etc. By real-time detection and feedback adjustment of the driving parameters of the conveying device 5, the tension of the electrode sheet is kept constant throughout the entire transmission path. Those skilled in the art can select appropriate tension control devices and control parameters according to factors such as electrode sheet material, width and coating speed, which will not be elaborated here.

[0039] Optionally, the coating drying equipment also includes a central controller, which is electrically connected to the low-speed circulation system and dehumidifier 32 of the first drying unit 1, the second drying unit 2 and the third drying unit 3 respectively. The central controller regulates the temperature, wind speed of each drying unit and the dew point temperature of the circulating air of the third drying unit 3 based on a preset algorithm.

[0040] See Figure 1 and Figure 2 Optionally, an isolation air curtain 4 is provided between adjacent drying units to achieve physical isolation, prevent the drying medium between adjacent drying units from flowing into each other, avoid mutual interference of process parameters such as temperature, wind speed, and humidity in each stage, and ensure that each drying stage can operate independently and stably.

[0041] Another embodiment of the present invention provides a sodium-ion battery electrode sheet, which is prepared by any of the coating and drying methods described above. Since the technical improvement of the sodium-ion battery electrode sheet prepared by the above method comes directly from the coating and drying method, and its beneficial effects are corresponding to those of the coating and drying method, it will not be described again here.

[0042] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A coating and drying method, characterized in that, The coated wet electrode sheet undergoes at least three functionally independent drying stages in sequence: The first stage uses a drying medium with a temperature of 70℃~90℃ and a wind speed of 5~15m / s to perform directional impact drying on the surface of the wet electrode to form a porous skeleton structure on the surface of the wet coating. The second stage uses a drying medium with a temperature of 100℃~130℃ and a wind speed of 2~5m / s to convectively dry the electrode sheets; The third stage involves circulating drying of the electrode sheets using a drying medium with a temperature of 130℃~160℃, a wind speed of 0.5~2m / s, and a dew point temperature ≤-20℃.

2. The coating and drying method according to claim 1, characterized in that, In the first stage, the airflow direction of the drying medium is perpendicular to the electrode surface or at an acute angle of ≤30° to the electrode's direction of travel.

3. The method according to claim 2, characterized in that, In the second stage, the airflow direction of the drying medium is parallel to the electrode.

4. The coating and drying method according to claim 3, characterized in that, Throughout the drying process, the tension of the control electrode is kept constant, with a tension value ranging from 20 to 100 N / m.

5. The coating and drying method according to claim 1, characterized in that, In the third stage, dehumidified dry air or nitrogen is introduced as the drying medium.

6. A coating and drying apparatus for implementing the coating and drying method according to any one of claims 1 to 5, characterized in that, It includes a first drying unit (1), a second drying unit (2) and a third drying unit (3) arranged sequentially along the direction of electrode travel; The first drying unit (1) includes an air outlet for generating high-speed directional impact air, the air outlet facing the surface of the electrode sheet; the second drying unit (2) includes a wind box for generating uniform parallel convection air; the third drying unit (3) includes a low-speed circulating air system (31), the circulating air system being connected to a dehumidifier unit (32).

7. The coating and drying equipment according to claim 6, characterized in that, The air outlet of the first drying unit (1) is a nozzle, and the air outlet direction of the nozzle is perpendicular to the surface of the electrode or forms an acute angle of ≤30° with the direction of travel of the electrode; the airflow direction generated by the air box of the second drying unit (2) is parallel to the electrode.

8. The coating and drying equipment according to claim 6, characterized in that, It also includes a tension control system, which is used to control the electrode tension to 20~100N / m on the electrode transport path.

9. The coating and drying equipment according to claim 6, characterized in that, An isolation air curtain (4) is installed between adjacent drying units to achieve physical isolation.

10. A sodium-ion battery electrode sheet, characterized in that, It is prepared by the coating and drying method according to any one of claims 1 to 5.

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