Non-contact stirring dry method electrode material fibration method and prepared pole piece

Abstract

The invention discloses a non-contact stirring dry method electrode material fibration method and a prepared pole piece. The principle that centrifugal force generated by autorotation and convection shear force caused by revolution are adopted, so that materials are uniformly mixed and fiberized by a'twisting 'and'pulling' force field generated under the condition of speed difference. The binder and the conductive agent are stirred and mixed for the first time in a non-contact mode, and the binder is coated with the conductive agent in advance; carrying out secondary non-contact stirring and mixing on the coated binder and the active substance particles to obtain a uniformly mixed pre-fibration material; carrying out uniform fibration treatment on the pre-fibration material, and then carrying out step-by-step hot pressing to obtain a dry-method electrode membrane; and performing hot-pressing compounding on the electrode film and a current collector containing a conductive agent to prepare the dry-method electrode plate. According to the non-contact stirring dry method electrode material fibration method, the length of a production line is shortened; the production cost is greatly reduced; the electrochemical performance is improved; and large-scale batch production can be realized.

Description

Technical Field

[0001] The invention relates to the technical field of lithium batteries, and in particular to a contactless stirring dry electrode material fiberization method and pole piece preparation. Background Art

[0002] In the current lithium battery manufacturing, the electrode stage mainly adopts the wet process, that is, the active material, conductive agent, and adhesive are mixed in a solvent in a certain proportion and process sequence, and then coated on the surface of the current collector and dried and rolled. Problems with the wet process: (1) High cost and high environmental pollution. The process uses N-methylpyrrolidone solvent, which is toxic and pollutes the environment. It needs to be recycled and consumes a lot of energy. According to statistics, the coating, drying and solvent recovery stages account for 22.76% and 53.99% of the equipment, labor, plant and energy costs respectively; (2) Electrode stratification. During the solvent evaporation process, the adhesive and conductive agent will float near the surface and form agglomerations through capillary action and diffusion, and the active material will precipitate, resulting in electrode stratification; (3) The thickness of the electrode is limited. The coating often leads to problems such as cracks, stratification, and poor flexibility, especially on thicker electrodes.

[0003] Based on the above problems, it is of great research significance to develop low-cost and environmentally friendly dry manufacturing technology. Dry manufacturing technology does not require solvents. The dry active particles, conductive agent and adhesive are mixed and hot pressed to form a dry electrode film under the fibrillation effect of the adhesive. Finally, they are hot pressed and composited on the surface of the current collector to form a pole piece. Its significant advantages are: (1) Cost advantage. Dry electrode manufacturing technology does not require a large amount of factory floor space to dry solvents, which greatly reduces the capital and manpower expenditures required by the factory. At the same time, not using solvents is more environmentally friendly and more suitable for large-scale production. According to statistics, the dry manufacturing process has fewer steps, the overall cost of battery cell manufacturing is reduced by 18%, the investment cost is reduced by more than 34%, and the electrode production area is reduced by more than 70%. This is one of the keys to reducing the production cost of lithium batteries through dry electrodes; (2) Improving electrode performance. By reducing inactive components, higher energy density can be achieved, and the electrical and mechanical properties of the battery are better.

[0004] However, in the preparation of dry electrodes, the binder exists in a fiberized state, so the fiberization of the binder is very critical. In most existing technologies, all materials are fiberized by methods such as airflow crushing and jet grinding. These fiberization methods use high shear force equipment, which not only leads to a decrease in the bonding function of the binder, but also leads to cracking of the surface of the active particles, particle breakage, and damage to the particle shape. Patents CN12420986A and CN115036449A use a variety of machines such as airflow mills, airflow crushing, screw extruders, and open mills to prepare electrodes by dry methods. Patent CN 112289976 A uses ultra-high shear speeds of 17000-25000rpm stirring for fiberization. The extremely high shear force in these technical methods will definitely have an adverse effect on the morphology and structure of the active particles.

[0005] Therefore, how to prepare a dry electrode material fiberization and pole piece preparation method with good fiberization degree, minimal or no damage to the microstructure of active materials, and no contact and pollution has become a key technology for solving problems in the field of lithium-ion battery manufacturing. It can also be said that dry electrode technology is considered the "holy grail" of lithium battery manufacturing technology. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention provides a dry electrode material fiberization method and electrode sheet preparation without contact stirring. The present invention adopts the principle of centrifugal force generated by rotation and convection caused by revolution to achieve the difference in direction and speed between revolution and rotation, and form a "pulling" and "rubbing" force field. Its significant advantage is that no stirring paddle of any form is used. Since no stirring paddle of any form is used, contactless and uniform mixing can be achieved. Its advantage is that it will not pollute the raw materials but also greatly reduce the degree of damage to the microstructure of the active materials, greatly reducing the occurrence of inactivation of active particles due to high shear force. The binder must first be "coated" with a conductive agent. The meaningful effect of this method is that the surface of the binder after fiberization is covered with a conductive agent. The most meaningful effect is that the conductive agent is embedded in the mesh and fibrous binder, which can greatly reduce the polarization phenomenon of the electrode in the electrical properties. Efficient mixing can be achieved, and the material mixing time is greatly shortened, which is currently measured in minutes. Constant temperature and a certain time are used for uniform fiberization, which reduces the unevenness of pre-fiberization, improves the forming speed of the fibrous network structure in the step-by-step hot pressing process, and avoids the problem that some binders cannot be formed during the hot pressing process due to lack of fiberization.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions: The present invention provides a contactless stirring dry-process electrode material fiberization method, which comprises the following steps: Step S1: coating of the binder: mixing the binder and the conductive agent for the first time by non-contact stirring, so as to achieve the pre-"coating" of the conductive agent on the binder; Step S2: pre-fiberization: mixing the pre-"coated" binder and the active material particles for a second time without contact stirring to obtain a pre-fiberized mixed material; Step S3: homogenizing the pre-fiberized mixed material for homogenizing the mixed material at a certain temperature for a certain period of time; Step S4: Step-by-step hot pressing to form a membrane: The uniformly fiberized material is hot pressed step-by-step to form a dry electrode membrane.

[0008] Furthermore, the contactless and non-stirring method in step S1 is any planetary mixer that uses the principle of self-rotation to generate centrifugal force and revolution to generate convective shear force to achieve uniform stirring of materials; the material tank of the planetary mixer is designed and installed to include a certain inclination angle, the inclination angle range is 10-80°, and there is no stirring paddle in the material tank.

[0009] Furthermore, the fiberizable binder in step S1 includes but is not limited to at least one of polytetrafluoroethylene, modified polytetrafluoroethylene, polyvinylidene fluoride, modified polyvinylidene fluoride, ethylene-tetrafluoroethylene, polyvinylidene fluoride, styrene-butadiene rubber, polyethylene oxide, poly(vinylidene fluoride-hexafluoropropylene), polyacrylonitrile, (methyl) polyacrylonitrile, polyacrylic acid, polymethyl methacrylate, modified polymethyl methacrylate, polyvinylidene fluoride copolymer, and polystyrene, that is, the binder can be a mixture of one or more of them.

[0010] Furthermore, the non-fibrillable binder in step S1 includes but is not limited to cellulose, cellulose acetate, suspended polytetrafluoroethylene, modified suspended polytetrafluoroethylene, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, nitrocellulose, carboxymethyl cellulose, carboxyethyl cellulose, carboxypropyl cellulose, carboxymethyl isopropyl cellulose, sodium cellulose, sodium nitrate cellulose and sodium carboxyalkyl cellulose.

[0011] Furthermore, in step S1, the binder is a mixture of one or more of the above, wherein the mass proportion of the fiberizable binder is 40%-100%.

[0012] Furthermore, the fiberizable binder in step S1 is a dispersed powder or micropowder, the particle size of which is not limited, the purity is greater than 99.9%, and the molecular weight is not less than 10 7 g / mol.

[0013] Furthermore, the conductive agent in step S1 includes but is not limited to at least one of carbon black conductive agent, conductive fiber, and conductive polymer.

[0014] Further, the active material in step S2 can be lithium cobalt oxide ternary material, nickel cobalt manganese ternary material, nickel cobalt aluminum ternary material, nickel cobalt aluminum manganese quaternary material, lithium-rich material, lithium iron phosphate, lithium iron manganese phosphate, graphite, hard carbon, activated carbon, soft carbon, graphene, silicon, silicon oxide, lithium titanate and their composite materials, etc., all positive electrode materials, negative electrode materials and mixed active materials for lithium batteries; Furthermore, in step S2, the mass percentage of the active material, the binder, and the conductive agent is (85% to 99%): (10% to 0.5%): (5% to 0.5%) (the total material amount is calculated as 100%).

[0015] Furthermore, the state of the material after pre-fiberization in step S2 is in or very close to "flocculation", "flocculation", or "lump".

[0016] Further, the method of contactless stirring and mixing in step S1 is: the first stage: the revolution speed is 100-3000rpm, the time is not less than 60s, and the revolution and rotation speed ratio is 20%-200%; the second stage: the revolution speed is 600rpm-3000rpm, the time is not less than 120s, and the revolution and rotation speed ratio is 40%-200%; the method of contactless stirring and mixing in step S2 is: the first stage: the revolution speed is 600-3000rpm, the time is not less than 120s, and the revolution and rotation speed ratio is 50%-200%; the second stage: the revolution speed is 300-1000rpm, the time is not less than 300s, and the revolution and rotation speed ratio is 30%-150%; the third stage: the revolution speed is 600-3000rpm, the time is not less than 300s, and the revolution and rotation speed ratio is 50%-200%.

[0017] Furthermore, in step S3, the material is fiberized at a temperature of 35-150° C. for a time of not less than 30 minutes.

[0018] Further, in step S4, the fiberized material is hot pressed step by step, the hot pressing temperature range is 30°C-200°C, the size parameter of each drop of the hot pressing roller gap is 50%-3% of the previous roller gap thickness value, and the adjustment value is adjusted in descending order, for example, the roller gap adjustment value can be 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, 65μm, 70μm, 75 μm, 80μm, 85μm, 90μm, 95μm, 100μm, 105μm, 110μm, 115μm, 120μm, 125μm, 130μm, 135μm, 140μm , 145μm, 150μm, 155μm, 160μm, 165μm, 170μm, 175μm, 180μm, 185μm, 190μm, 195μm, 200μm and above.

[0019] Furthermore, the electrode film in step S4 has a certain toughness or strength, and its tensile strength should be not less than 5 N / mm 2 .

[0020] Furthermore, in step S4, the thickness of the electrode film is about 50 μm-5 mm.

[0021] Furthermore, in step S4, the surface of the electrode film is smooth and flat, and is substantially free of defects such as holes, curls, wrinkles, pores, cracks, pits, protrusions, dark marks, black spots, linear traces, and the like.

[0022] The present invention also provides an electrode sheet, which is obtained by hot pressing the dry electrode film prepared above and a current collector coated with a conductive agent, and the hot pressing temperature is controlled within the range of 60-200°C.

[0023] Compared with the prior art, the present invention has at least the following beneficial effects: (1) The present invention adopts the principle of centrifugal force generated by rotation and shear force formed by convection caused by revolution to achieve the difference in direction and speed of revolution and rotation, forming a "pulling" and "rubbing" force field. Its significant advantage is that it does not use any form of stirring paddle and can achieve uniform mixing of materials.

[0024] (2) The present invention does not use any form of stirring paddle, so it can achieve contactless uniform mixing. Its advantages are that it will not pollute the raw materials and greatly reduce the degree of damage to the microstructure of the active material, thereby avoiding the inactivation of the active substance due to high shear force.

[0025] (3) The present invention firstly treats the binder with a conductive agent "coating" to achieve uniform "coating" of the binder surface by the conductive agent. The most significant effect is that the conductive agent is covered on the binder surface after fiberization, and the conductive agent is embedded in the fiber filaments, which can greatly reduce the polarization of the electrode in the electrochemical process.

[0026] (4) The method of the present invention is efficient in mixing, saves time and cost, completes the fiberization of powder in a relatively short time, and greatly shortens the material mixing and preparation time.

[0027] (5) The method of the present invention uses a constant temperature for a certain period of time to perform uniform fiberization, which reduces the unevenness of fiberization and increases the molding speed of the step-by-step hot pressing process; it can also reduce the problem of being unable to form during the hot pressing process due to partial lack of fiberization. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a digital photo of the conductive agent coated with the binder in Example 1; Figure 2 This is a digital photo of the conductive agent coated with the binder in Comparative Example 1; Figure 3 This is a digital photo of the pre-fiberized material in Example 1; Figure 4 This is a digital photo of the pre-fiberized material of Comparative Example 1; Figure 5 This is a 10,000-fold magnified cross-sectional view of the pole piece of Example 1 after hot pressing, taken with a scanning electron microscope; Figure 6 This is a 10,000-fold magnified surface image of the electrode after hot pressing in Example 2 using a scanning electron microscope; Figure 7 This is a digital photo of the electrode after hot pressing in comparative example 2; Figure 8 This is a digital photo of the electrode after hot pressing in Example 3; Fig. 9 This is a digital photo of comparative example 3 after rolling; Fig.10 This is a 2000 times magnified cross-sectional view of the pole piece of Example 4 after hot pressing under a scanning electron microscope; Fig.11 Comparative Example 4: Digital photo after roller pressing; Fig.12 Digital photo of the material after prefiberization in Comparative Example 5; Fig.13 Digital photo of comparative example 5 after rolling; DETAILED DESCRIPTION

[0029] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or are obtained by practicing the present invention. It should be understood by those skilled in the art that the specific embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0030] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0031] Example 1 The dry electrode membrane of this embodiment is composed of the following components in mass ratio: ternary material NCM622: polytetrafluoroethylene (powder): conductive carbon black = 85:10:5, the total mass is controlled to be 100g, the molecular weight of the binder is 10 6 g / mol or more, and the particle size D50 is 10μm.

[0032] The fiberization method of the material is as follows: (1) The binder and the conductive agent are mixed for the first time, with the mass ratio of the binder to the conductive agent being 10:5. The mixture is first mixed at a revolution speed of 300 rpm for 120 s, with a revolution speed ratio of 70%; then the mixture is mixed at a revolution speed of 600 rpm for 180 s, with a revolution speed ratio of 50%; (2) The binder coated with the conductive agent is mixed with the active material particles for a second time, with the mass ratio of the active material, the binder and the conductive agent being 85:10:5. The mixture is firstly rotated at a speed of 1200 rpm for 120 s and a rotation speed ratio of 50%; then the mixture is rotated at a speed of 600 rpm for 300 s and a rotation speed ratio of 50%; finally the mixture is rotated at a speed of 1600 rpm for 300 s and a rotation speed ratio of 100% to obtain a pre-fiberized "flocculated", "flocculated" and "lump-shaped" mixed material; (3) subjecting the mixture in (2) to homogenization treatment at 60°C for 1 h; (4) The fiberized material is hot-pressed step by step at 80°C, and the roll gap is adjusted to 20% of the previous roll gap thickness each time to form an electrode film.

[0033] The electrode film prepared in this embodiment is composited with a current collector containing a conductive agent by hot pressing at 150° C. to obtain a dry-process electrode sheet.

[0034] Example 2 The difference between Example 2 and Example 1 is that the ternary material in Example 1 is replaced by graphite, and the remaining steps are the same as Example 1.

[0035] Example 3 The difference between Example 3 and Example 1 is that the particle size D50 of the binder is 30 μm and the molecular weight is greater than 6×10 7 g / mol, and the remaining steps are the same as in Example 1.

[0036] Example 4 The difference between Example 4 and Example 2 is that the particle size D50 of the binder is 30 μm and the molecular weight is greater than 6×10 7 g / mol, and the remaining steps are the same as in Example 2.

[0037] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the molecular weight of the binder is 10000-800000 g / mol, D50 is 10 μm, and the remaining steps are the same as Example 1.

[0038] Comparative Example 2 The difference between Comparative Example 2 and Example 2 is that the molecular weight of the binder is 10000-800000 g / mol, D50 is 10 μm, and the remaining steps are the same as Example 2.

[0039] Comparative Example 3 The difference between Comparative Example 3 and Example 3 is that the fiberized material is hot-pressed step by step, and the roll gap is adjusted to 55% of the previous roll gap thickness each time, and the remaining steps are the same as Example 3.

[0040] Comparative Example 4 The difference between Comparative Example 4 and Example 4 is that the molecular weight of the binder is 10000-800000 g / mol, D50 is 30 μm, and the remaining steps are the same as Example 4.

[0041] Comparative Example 5 This comparative example is composed of the following components in mass ratio: ternary material: polytetrafluoroethylene (powder): conductive carbon black = 85:10:5, total mass control 100g, binder molecular weight 10 7 g / mol or more, and the particle size D50 is 10μm.

[0042] Compared with Example 1, the fiberization method of the material is to mix the active material, the binder, and the conductive agent together, as follows: (1) The active material, binder and conductive agent are mixed for the first time, and the mass ratio of the ternary active material, binder and conductive agent is 85:10:5. The mixture is first mixed at an orbital speed of 300 rpm for 120 s and an orbital rotation speed ratio of 70%. Then, the mixture is mixed at an orbital speed of 600 rpm for 180 s and an orbital rotation speed ratio of 50%. (2) The materials obtained in (1) were mixed for the second time, with the mass ratio of active material: binder: conductive agent being 85:10:5. The mixture was first mixed at a revolution speed of 1200 rpm for 120 s and a revolution speed ratio of 50%; then mixed at a revolution speed of 600 rpm for 300 s and a revolution speed ratio of 50%; and finally mixed at a revolution speed of 1600 rpm for 300 s and a revolution speed ratio of 100%. (3) subjecting the material in (2) to homogenization treatment at 60°C for 1 h; (4) The fiberized material is hot-pressed step by step, and the roll gap is adjusted each time to 20% of the previous roll gap thickness to form an electrode film; the specific method is the same as step (4) of Example 1.

[0043] The obtained electrode film and the current collector containing the conductive agent were hot-pressed and compounded at 150° C. to obtain a dry-process electrode sheet.

[0044] The scanning electron microscope and digital photos of the powders or electrode films after rolling prepared in Examples 1 to 4 and Comparative Examples 1 to 5 are as follows: Figure 1-11 shown. Figure 1 This is a digital photo of the adhesive in Example 1 after being coated with a conductive agent. Figure 1 It can be seen from the photos that the surface of the binder particles is evenly coated with carbon black, and the particle size is relatively uniform; Figure 2 In Example 1, the binder is coated with carbon black, the particle size is uneven, most of the particles do not have a complete shape, the carbon black and binder particles are in a mixed state, and in this state, they are mixed multiple times without the appearance of Figure 1 Status shown.

[0045] Figure 3 This is a digital photo of the material after pre-fiberization in Example 1. The material appears "flocculated" or "surface-flocculated", and there is a certain degree of stickiness or filaments between the floccules; Figure 4 This is a digital photo of the pre-fiberized material of Example 1. The materials are in a loose state, and the binder does not exert the corresponding adhesion. It is preliminarily judged that the binder is not fiberized.

[0046] Figure 5 This is a scanning electron microscope image of the cross-section of the electrode membrane in Example 1 magnified 10,000 times. It can be seen that there are more and more obvious fiberization, the fiber filaments are relatively long, and there are no breaks in the middle. The fiber filaments tightly connect the active particles and the conductive agent together to form an electrode membrane. The most obvious thing is that many tiny conductive carbon black particles are connected in series in the fiber filaments, which greatly enhances the conductive effect of the electrode.

[0047] Figure 6 This is a scanning electron microscope image of the electrode surface in Example 2 magnified 10,000 times. There are obvious filamentous and fibrous substances on the surface of the electrode film. The fiber diameter is relatively uniform and thin. The uniform fiber connects the particles together to form an electrode film. Figure 7 This is a digital photo of the electrode film in Example 2. The electrode film can hardly be formed, and there are many cracks and fissures on the surface of the electrode.

[0048] Figure 8 This is a digital photo of the electrode film in Example 3. The surface of the electrode film is uniformly smooth and bright, without defects such as cracks, black spots, protrusions, holes, etc.; Fig. 9 This is a digital photo of the electrode film in Example 3. The surface of the electrode is relatively smooth and has no cracks, but there are many black spots on the surface, and the distribution of the black spots is uneven, and the size of the black spots varies; Fig.10 This is a scanning electron microscope of the electrode membrane in Example 4 magnified 2000 times. There are many and evenly distributed fibers inside the electrode membrane, and the binder is evenly fiberized; Fig.11 This is the electrode film after hot pressing in Example 4. It can be seen from the figure that the electrode film is relatively brittle and no effective connecting wires can be formed between the materials, resulting in the inability to form the electrode film.

[0049] Fig.12 This is a digital photo of the material after pre-fiberization in Comparative Example 5, compared with Example 1 ( Figure 1 ) are obviously different. There is a small amount of "small flocculent" material in the material, and the rest of the materials are relatively dispersed without obvious agglomeration. Fig.13 This is a digital photo of the electrode film after step-by-step hot pressing in Example 5. It can be seen that there are black spots and black dots on the surface of part of the electrode film, which are irregular in shape and unevenly distributed.

[0050] The above embodiments of the present invention are for inspiration. Through the above description, relevant technicians can make various changes and modifications without departing from the technical concept of the present invention. The technical scope of the present invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A non-contact stirring dry electrode material fiberization method, characterized in that: The following steps are involved: S1 Binder coating: The binder and the conductive agent are mixed by non-contact stirring to achieve surface coating of the binder by the conductive agent; S2 pre-fiberization: mixing the binder coated with the conductive agent with the active material particles by non-contact stirring to obtain a pre-fiberized material; S3 homogenization: homogenization treatment of the pre-fiberized material at a certain temperature for a certain period of time; S4 step-by-step hot pressing film formation: The fiberized material is subjected to step-by-step hot pressing to form a dry electrode tough film.

2. The non-contact stirring dry electrode material fiberization method according to claim 1, characterized in that: The contactless mixing is achieved by using any planetary mixer that generates centrifugal force by rotation and convective shear force by revolution to achieve uniform mixing of materials; the material tank of the planetary mixer has an inclination angle of 10-80° and there is no stirring paddle in the material tank.

3. The non-contact stirring dry electrode material fiberization method according to claim 1, characterized in that: The binder in S1 comprises at least one binder that can be fiberized, which accounts for 40%-100% of the total binder. The binder that can be fiberized is a dispersed powder or micro powder, and its particle size is not limited, the purity is greater than 99.9%, and the molecular weight is not less than 10 7 g / mol, and the fiberizable binder includes at least one of polytetrafluoroethylene, modified polytetrafluoroethylene, polyvinylidene fluoride, modified polyvinylidene fluoride, ethylene-tetrafluoroethylene, polyvinylidene fluoride, styrene-butadiene rubber, polyethylene oxide, poly(vinylidene fluoride-hexafluoropropylene), polyacrylonitrile, (methyl)polyacrylonitrile, polyacrylic acid, polymethyl methacrylate, modified polymethyl methacrylate, polyvinylidene fluoride copolymer, and polystyrene.

4. The non-contact stirring dry electrode material fiberization method according to claim 1, characterized in that: The conductive agent in S1 includes at least one of carbon black conductive agent, conductive fiber, and conductive polymer.

5. The non-contact stirring dry electrode material fiberization method according to claim 1, characterized in that: The active material in S2 is at least one of lithium cobalt oxide ternary material, nickel cobalt manganese ternary material, nickel cobalt aluminum ternary material, nickel cobalt aluminum manganese quaternary material, lithium-rich, lithium iron phosphate, lithium iron manganese phosphate, graphite, hard carbon, soft carbon, activated carbon, graphene, silicon, silicon oxide, and lithium titanate.

6. The non-contact stirring dry electrode material fiberization method according to claim 1, characterized in that: In the step S2, based on 100% of the total material amount, the mass percentages of the active material, the binder, and the conductive agent are (85% to 99%): (10% to 0.5%): (5% to 0.5%).

7. The non-contact stirring dry electrode material fiberization method according to claim 1, characterized in that: The method of contactless stirring and mixing in step S1 is: the first stage: the revolution speed is 100-3000rpm, the time is not less than 60s, and the revolution and rotation speed ratio is 20%-200%; the second stage: the revolution speed is 600rpm-3000rpm, the time is not less than 120s, and the revolution and rotation speed ratio is 40%-200%; the method of contactless stirring and mixing in step S2 is: the first stage: the revolution speed is 600-3000rpm, the time is not less than 120s, and the revolution and rotation speed ratio is 50%-200%; the second stage: the revolution speed is 300-1000rpm, the time is not less than 300s, and the revolution and rotation speed ratio is 30%-150%; the third stage: the revolution speed is 600-3000rpm, the time is not less than 300s, and the revolution and rotation speed ratio is 50%-200%.

8. The non-contact stirring dry electrode material fiberization method according to claim 1, characterized in that: In step S3, the material is fiberized at a temperature of 35-150°C for a period of not less than 30 minutes.

9. The non-contact stirring dry electrode material fiberization method according to claim 1, characterized in that: In step S4, the fiberized material is subjected to step-by-step hot pressing at a temperature range of 35°C-200°C. In step S4, the fiberized material is subjected to step-by-step hot pressing. The hot pressing decreases step-by-step in proportion. The roller gap decrease adjustment value parameter is 50%-3% of the previous roller gap thickness value. The adjustment value is performed in descending order.

10. A dry electrode sheet, characterized in that The electrode toughness film is prepared by the method described in any one of claims 1 to 9, specifically, the electrode toughness film is hot-pressed and composited with a current collector coated with a conductive agent to form a dry electrode sheet, and the hot-pressing composite temperature is 60-200°C.

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