Fibrous fluffy powder, method for preparing the same, and lithium ion battery

Abstract

This invention provides a fibrous fluffy powder, its preparation method, and a lithium-ion battery. The preparation method includes: (1) mixing an active material and a conductive agent to obtain a first mixture; (2) adding a first binder to the first mixture in step (1) for a second mixing to obtain a second mixture; (3) adding a second binder solution to the second mixture in step (2) for a third mixing to obtain a third mixture; and (4) subjecting the third mixture in step (3) to a fourth mixing followed by heat treatment to obtain the fibrous fluffy powder. The preparation method of this invention is simple and easy to implement, can improve the degree of powder fibroidization, and the prepared fibrous fluffy powder has good film-forming properties, which better improves the strength of the film and reduces the powder shedding of the film.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion batteries and relates to a method for preparing fibrous fluffy powder, particularly to a fibrous fluffy powder, its preparation method, and a lithium-ion battery. Background Technology

[0002] With the development of new energy entering a boom, lithium-ion power battery vehicles and energy storage have become the two main applications of lithium-ion batteries in the new era. The market demand is increasingly inclined towards high energy density and high power. The manufacturing of lithium batteries mainly involves two technological innovations: new materials and new processes.

[0003] In process development, a dry electrode technology, distinct from wet-process battery manufacturing, has been a key focus of research and is planned for application in this field. Dry electrode technology uses little or no solvent, significantly reducing energy consumption and solvent recovery costs compared to wet processes. It also eliminates the need for tens of meters of baking channels, lowering investment costs and thus offering a cost advantage. Furthermore, dry electrodes can be fabricated to be thicker, freeing the electrode sheet from the limitations of coating thickness. The equipment used to achieve this technology differs from that used in wet coating processes, being more precise and complex. The front-end processes for electrode sheet fabrication are entirely different from those in wet processes.

[0004] CN113871566A discloses a dry electrode film, its preparation method, and its application. An active material, a conductive agent, and a polymer film are mixed uniformly to obtain a mixture. This mixture is then subjected to a fiberization process to obtain a final product. Finally, the final product is subjected to a heat-calendering process to prepare the dry electrode film.

[0005] CN115275115A discloses a dry electrode, its preparation method, and its application. An active material and a conductive agent are dry-mixed to obtain a mixture. A binder and ethanol solvent are added and kneaded to obtain a dough-like mixture. This dough-like mixture is coated onto the surface of a composite foil, preheated and pressed, then subjected to high-temperature hot pressing. The dry electrode is obtained through slitting, die-cutting, baking, and stacking.

[0006] In dry electrode preparation, fiberization after dry powder mixing is a crucial process. Currently, the market mainly uses high-speed mixing and air-flow mixing to achieve fiberization of dry electrode powder through a single pulverization. This requires a high shear rate in the mixing equipment, which not only causes significant wear and tear on the equipment and high energy consumption, but more importantly, the high shear strength can damage the structure of the active material and affect the electrochemical performance of lithium-ion batteries. However, slightly lower shear strength is insufficient to achieve adequate fiberization, which is not feasible for dry electrode preparation.

[0007] Therefore, improving the degree of powder fiberization in dry mixing to prepare better dry electrode films is an important research direction in this field. Summary of the Invention

[0008] The purpose of this invention is to provide a fibrous and fluffy powder for improving the degree of powder fibrosis, a method for preparing the same, and a lithium-ion battery.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] One objective of this invention is to provide a method for preparing fibrous fluffy powder, the method comprising:

[0011] (1) The active material and the conductive agent are mixed in a first mixture to obtain a first mixture;

[0012] (2) Add the first adhesive to the first mixture in step (1) and mix it a second time to obtain the second mixture;

[0013] (3) Add the second adhesive solution to the second mixture in step (2) for a third mixing to obtain a third mixture;

[0014] (4) The third mixture in step (3) is subjected to a fourth mixing and heating treatment to obtain the fibrous fluffy powder.

[0015] In this invention, step (1) involves mixing the active material with the conductive agent, which increases the conductivity inside the electrode. The first binder in this invention has fibrous properties. Steps (2) and (3) involve adding the binder twice for mixing, facilitating the dispersion of different binders and achieving different powder friction coefficients at different stages. This allows the unfibrillated portion of the first binder to become fibrous, realizing the interaction between the second and first binders. Step (4) involves a fourth mixing of the third mixture, further enhancing the fibrous nature of the first binder. The powder after the fourth mixing is then heat-treated, resulting in a distinct spiderweb-like texture, indicating that most of the binder has achieved a high degree of fibrousization.

[0016] The preparation method of this invention is simple and easy to implement, improves the degree of fiberization of powder, reduces the speed of high-speed mixing equipment during mixing, reduces the requirements for equipment, reduces equipment wear and energy consumption. The fiberized and fluffy powder prepared by the preparation method of this invention has good film-forming properties, better improves the strength of the film, and avoids the shedding of powder from the film.

[0017] As a preferred technical solution of the present invention, the mass ratio of the active material, conductive agent in step (1), the first adhesive in step (2), the first adhesive in step (2), and the second adhesive in the solution of the second adhesive in step (3) is (92.5~97.5):(0.1~1):(0.9~5):1.5, wherein the mass ratio can be 92.5:1:5:1.5, 93:1:4.5:1.5, 94:0.5:4:1.5, 95:1:2.5:1.5, 96:0.5:2:1.5, 97:0.1:1.4:1.5, or 97.5:0.1:0.9:1.5, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0018] Preferably, the active material in step (1) includes a positive electrode active material or a negative electrode active material.

[0019] Preferably, the negative electrode active material includes graphite and / or silicon-based materials.

[0020] Preferably, the graphite includes natural graphite and / or artificial graphite.

[0021] Preferably, the silicon-based material includes silicon-oxygen materials and / or silicon-carbon materials.

[0022] Preferably, the positive electrode active material includes any one or a combination of at least two of LFP, NCM, or LiCoO3, wherein typical but non-limiting examples of the combination include: a combination of LFP and NCM, a combination of NCM and LiCoO3, or a combination of LFP and LiCoO3, etc.

[0023] Preferably, the conductive agent in step (1) includes any one or a combination of at least two of conductive carbon black, acetylene black, Ketjen black, graphite, carbon nanofibers, single-walled carbon nanotubes, multi-walled carbon nanotubes, or graphene. Typical but non-limiting examples of such combinations include: a combination of conductive carbon black and acetylene black, a combination of Ketjen black and graphite, a combination of carbon nanofibers and single-walled carbon nanotubes, a combination of single-walled carbon nanotubes and multi-walled carbon nanotubes, or a combination of multi-walled carbon nanotubes and graphene, etc.

[0024] As a preferred technical solution of the present invention, in step (1), the first mixing is carried out in a granulator. The cutting speed of the granulator is 150 to 3000 rpm. The cutting speed can be 150 rpm, 200 rpm, 300 rpm, 500 rpm, 700 rpm, 900 rpm, 1000 rpm, 1200 rpm, 1400 rpm, 1600 rpm, 1800 rpm, 2000 rpm, 2200 rpm, 2400 rpm, 2600 rpm, 2800 rpm, or 3000 rpm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable, preferably 800 to 1500 rpm.

[0025] Preferably, in step (1), the first mixing is carried out in a granulator, wherein the scraper speed of the granulator is 50 to 300 rpm, wherein the scraper speed can be 50 rpm, 80 rpm, 100 rpm, 120 rpm, 140 rpm, 160 rpm, 180 rpm, 200 rpm, 220 rpm, 240 rpm, 260 rpm, 280 rpm or 300 rpm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable, preferably 150 to 300 rpm.

[0026] Preferably, the mixing time in step (1) is 1 to 60 minutes, wherein the time can be 1 minute, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes or 60 minutes, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable, preferably 10 to 20 minutes.

[0027] As a preferred technical solution of the present invention, the first adhesive in step (2) includes polytetrafluoroethylene dispersion resin.

[0028] This invention selects polytetrafluoroethylene (PTFE) dispersion resin as the first binder. PTFE dispersion resin has fibrous properties; under certain shear strength or temperature, its original crystal structure undergoes a phase transition, transforming from primary particles into fibrous filaments. This invention achieves fibrousization of the first binder by first mixing it, thus changing its surface state, and then mixes it with the second binder, facilitating the interaction between the second and first binders.

[0029] As a preferred technical solution of the present invention, the mixing time in step (2) is 1 to 20 minutes, wherein the time can be 1 minute, 2 minutes, 4 minutes, 6 minutes, 8 minutes, 10 minutes, 12 minutes, 14 minutes, 16 minutes, 18 minutes or 20 minutes, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0030] Preferably, step (2) the second mixing is carried out in a mixer.

[0031] Preferably, in step (2), the rotational speed of the second mixing is 1500 to 45000 rpm, wherein the rotational speed can be 1500 rpm, 3000 rpm, 4500 rpm, 6000 rpm, 7500 rpm, 9000 rpm, 10500 rpm, 12000 rpm, 15000 rpm, 20000 rpm, 25000 rpm, 30000 rpm, 35000 rpm, 40000 rpm, or 45000 rpm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable, preferably 3000 to 30000 rpm.

[0032] In this invention, the rotational speed of the second mixing is matched with the size of the material cylinder and the size of the dispersing blade, and the linear velocity at the middle position of the blade edge needs to be greater than 30m / s.

[0033] As a preferred technical solution of the present invention, in step (3), the solute of the second binder solution is a second binder, which includes any one or at least two of PVP powder, PAA powder, PEG powder, CMC powder, PVDF powder, PVP emulsion, PAA emulsion, PEG emulsion, CMC emulsion or PVDF emulsion. Typical but non-limiting examples of such combinations include: a combination of PVP powder and PAA powder, a combination of PEG powder and CMC powder, a combination of PVP adhesive and PAA adhesive, a combination of PEG adhesive and CMC adhesive, or a combination of PVDF adhesive and PAA powder, etc.

[0034] Preferably, the solvent used in the second adhesive solution in step (3) includes any one or a combination of at least two of deionized water, N-methylpyrrolidone, volatile alcohol solvents or volatile silicone oil solvents, wherein typical but non-limiting examples of the combination are: a combination of deionized water and volatile alcohol solvents or a combination of N-methylpyrrolidone and volatile silicone oil solvents.

[0035] The purpose of selecting the second binder solution in this invention is to facilitate better dispersion and dissolution of the second binder, allowing the macromolecular chains to extend. Selecting the type of second binder can better improve the quality of the electrode and the battery's first efficiency and other electrochemical performance.

[0036] Preferably, in step (3), the mass fraction of the second adhesive in the second adhesive solution is 1% to 40%, wherein the mass fraction can be 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, or 40%, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0037] As a preferred technical solution of the present invention, the revolution speed of the third mixture in step (3) is 15 to 30 rpm, wherein the revolution speed can be 15 rpm, 18 rpm, 20 rpm, 22 rpm, 24 rpm, 26 rpm, 28 rpm or 30 rpm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0038] Preferably, the solid content of the third mixed material is 72-95%, wherein the solid content can be 72%, 74%, 76%, 78%, 80%, 82%, 84%, 86%, 88%, 90%, 92%, 94% or 95%, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0039] Preferably, the third mixture in step (3) is dried. Preferably, the drying temperature is 45-150°C, wherein the temperature can be 45°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C or 150°C, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0040] Preferably, the drying time is 0.5 to 3 hours, wherein the time can be 0.5 hours, 1 hour, 1.5 hours, 2 hours, 2.5 hours or 3 hours, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0041] In this invention, the product is further air-dried after drying.

[0042] In this invention, a forced-air drying oven is selected as the drying equipment. The function of the forced-air drying oven is to dry the powder and also to help increase fiberization.

[0043] As a preferred technical solution of the present invention, the fourth mixing time in step (4) is 0.5 to 20 min, wherein the time can be 0.5 min, 1 min, 2 min, 4 min, 6 min, 8 min, 10 min, 12 min, 14 min, 16 min, 18 min or 20 min, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0044] Preferably, the speed of the fourth mixing in step (4) is 1500 to 45000 rpm, wherein the speed can be 1500 rpm, 3000 rpm, 4000 rpm, 5000 rpm, 10000 rpm, 15000 rpm, 20000 rpm, 25000 rpm, 30000 rpm, 35000 rpm, 40000 rpm or 45000 rpm, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable, preferably 3000 to 30000 rpm.

[0045] In this invention, the rotational speed of the fourth mixing process must match the size of the material cylinder and the size of the dispersing blade to ensure that the linear velocity at the center of the blade edge is greater than 30 m / s.

[0046] In this invention, the fourth mixing method is adopted by high-speed shear mixing, and after the fourth mixing, an ultra-fluffy and soft powder is obtained.

[0047] Preferably, the temperature of the heating treatment in step (4) is 60 to 120°C, wherein the temperature can be 60°C, 70°C, 80°C, 90°C, 100°C, 110°C or 120°C, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0048] The fourth mixture of the present invention is heated, and the powder after the treatment exhibits obvious spider web-like filaments, and most of the binder achieves a high degree of fiberization.

[0049] A second objective of this invention is to provide a fibrous fluffy powder, which is prepared by the method for preparing fibrous fluffy powder as described in one objective.

[0050] The third objective of this invention is to provide a lithium-ion battery, the lithium-ion battery comprising an electrode membrane, the electrode membrane being prepared from the fibrous fluffy powder as described in the second objective.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] (1) The fibrous fluffy powder prepared by the present invention has good film-forming properties and good strength, which can reach 0.45 MPa;

[0053] (2) The preparation method of the fibrous fluffy powder of the present invention is simple and easy to implement, and can improve the degree of fibrosis of the powder;

[0054] (3) The preparation process of the fibrous fluffy powder of the present invention has low requirements for equipment, which can reduce equipment wear and energy consumption. Attached Figure Description

[0055] Figure 1 This is a SEM image of the fibrous fluffy powder in Example 1 of the present invention. Detailed Implementation

[0056] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0057] Example 1

[0058] This embodiment provides a method for preparing fibrous fluffy powder. The raw materials are: artificial graphite, conductive carbon black, polytetrafluoroethylene powder, and PVP powder-deionized water in a mass ratio of 95:1:2.5:1.5. The specific preparation method includes the following steps:

[0059] (1) Artificial graphite and conductive carbon black are mixed for the first time to obtain a first mixture, wherein the cutting speed of the first mixture is 1200 rpm, the scraper speed is 220 rpm, and the time is 15 min;

[0060] (2) Add polytetrafluoroethylene dispersion resin to the first mixture in step (1) for a second mixing to obtain a second mixture, wherein the rotation speed of the second mixing is 25000 rpm and the time is 15 min;

[0061] (3) Add the second binder solution prepared by PVP powder-deionized water with a mass fraction of 20% to the second mixture in step (2) for a third mixing to obtain a third mixture. The third mixing speed is 25 rpm, and the solid content of the material after the third mixing is 86%. The material after the third mixing is dried by blowing air drying at a temperature of 85°C and a time of 30 min.

[0062] (4) The third mixture in step (3) is mixed for 10 minutes at a speed of 20,000 rpm and then heated at 85°C to obtain the fibrous fluffy powder.

[0063] The SEM image of the fibrous fluffy powder obtained in this embodiment is as follows: Figure 1 As shown.

[0064] Example 2

[0065] This embodiment provides a method for preparing fibrous fluffy powder. The raw materials are: natural graphite, Ketjen black, polytetrafluoroethylene dispersion resin, and PAA powder in an ethanol solution with a PAA powder mass ratio of 97.5:0.1:0.9:1.5. The specific preparation method includes the following steps:

[0066] (1) Natural graphite and Ketjen black are mixed for the first time to obtain a first mixture. The cutting speed of the first mixture is 150 rpm, the scraper speed is 50 rpm, and the time is 60 min.

[0067] (2) Add polytetrafluoroethylene to the first mixture in step (1) for a second mixing to obtain a second mixture, wherein the rotation speed of the second mixing is 1500 rpm and the time is 20 min;

[0068] (3) Add 1% PAA powder-ethanol solution to the second mixture in step (2) for a third mixing to obtain a third mixture. The third mixing speed is 25 rpm. The solid content of the material after the third mixing is 72%. The material after the third mixing is dried by forced air drying at a temperature of 45°C for 3 hours.

[0069] (4) The third mixture in step (3) is mixed for 20 minutes at a speed of 1500 rpm and then heated at 60°C to obtain the fibrous fluffy powder.

[0070] Example 3

[0071] This embodiment provides a method for preparing fibrous fluffy powder. The raw materials are: LiCoO3, single-walled carbon nanotubes, polytetrafluoroethylene dispersion resin, and PVDF powder in an N-methylpyrrolidone solution with a mass ratio of 92.5:1:5:1.5. The specific preparation method includes the following steps:

[0072] (1) LiCoO3 and single-walled carbon nanotubes are mixed for the first time to obtain the first mixture. The cutting speed of the first mixing is 3000 rpm, the scraper speed is 300 rpm, and the time is 1 min.

[0073] (2) Add polytetrafluoroethylene dispersion resin to the first mixture in step (1) for a second mixing to obtain a second mixture, wherein the rotation speed of the second mixing is 45000 rpm and the time is 1 min;

[0074] (3) Add 40% PVDF powder-N-methylpyrrolidone solution to the second mixture in step (2) for a third mixing to obtain a third mixture. The third mixing speed is 30 rpm. The solid content of the material after the third mixing is 95%. The third mixture is dried by blowing air. The drying temperature is 150℃ and the time is 30 min.

[0075] (4) The third mixture in step (3) is mixed for 0.5 min at a speed of 45000 rpm and then heated at 120°C to obtain the fibrous fluffy powder.

[0076] Example 4

[0077] In this embodiment, except that the PVP powder in step (3) is replaced with SBR emulsion, all other conditions are the same as in Example 1.

[0078] Example 5

[0079] In this embodiment, except that the PVP powder-deionized water with a mass fraction of 20% in step (3) is replaced with PVP powder, all other conditions are the same as in Example 1.

[0080] Example 6

[0081] In this embodiment, the only difference is that the temperature of the heating treatment in step (4) is replaced with 30°C, and all other conditions are the same as in embodiment 1.

[0082] Example 7

[0083] In this embodiment, the only difference is that the temperature of the heating treatment in step (4) is replaced with 140°C. All other conditions are the same as in embodiment 1.

[0084] Comparative Example 1

[0085] Except for step (2), the conditions in this comparative example are the same as those in Example 1.

[0086] Comparative Example 2

[0087] Except for step (3), the conditions in this comparative example are the same as those in Example 1.

[0088] Comparative Example 3

[0089] Except for step (4), the conditions in this comparative example are the same as those in Example 1.

[0090] The fibrous fluffy powders prepared in Examples 1-2, 4-7 and Comparative Examples 1-3 were used to prepare negative electrode films, and the fibrous fluffy powders prepared in Example 3 were used to prepare positive electrode films. The method for preparing negative electrode films from the fibrous fluffy powders in Examples 1-2, 4-7 and Comparative Examples 1-3 was as follows: first, the powder was fibrousized, and then calendered into films.

[0091] The positive or negative electrode films prepared in Examples 1-7 and Comparative Examples 1-3 were tested for electrode film strength. The specific test method for tensile strength was as follows: a universal tensile testing machine (gravity meter with a range of 50N, cut standard size sample: length * width = 100mm * 20mm, gauge length 50mm) was used to test the electrode film strength.

[0092] The membrane strength test results of Examples 1-7 and Comparative Examples 1-3 of the present invention are shown in Table 1.

[0093] Table 1

[0094]

[0095]

[0096] The table above shows that secondary fiberization significantly improves fiberization. When combined with other binders, the improvement in fiberization is even more pronounced, resulting in better strength of the film.

[0097] Comparing Example 1 and Example 4, it can be seen that after replacing PVP powder with SBR emulsion in step (3), the film-forming properties of the fiberized powder deteriorated, indicating that the film strength is related to the type of compound binder. Direct addition of SBR emulsion cannot increase the fiberization effect, and the type of compound binder has a certain influence on the fiberization effect.

[0098] Comparing Example 1 and Example 5, it can be seen that replacing the 20% PVP powder-deionized water in step (3) with PVP powder indicates that the secondary fiberization effect can only be achieved after the compound binder is dispersed by the influence of the solution. Direct addition of dry powder cannot increase the fiberization effect. That is, the improvement of membrane strength is directly related to the secondary fiberization process.

[0099] A comparison of Example 1 and Examples 6-7 shows that if the temperature of the heating treatment in step (4) is too high or too low, it is not conducive to the film processing, and the corresponding film strength is lower than the optimal temperature range.

[0100] As can be seen from the comparison between Example 1 and Comparative Examples 1-3, other powder preparation methods cannot achieve the dry film processing strength of this method.

[0101] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing fibrous fluffy powder, characterized in that, The preparation method includes: (1) The active material and the conductive agent are mixed for the first time to obtain the first mixture; (2) The first binder is added to the first mixture in step (1) for a second mixing to obtain a second mixture; the first binder includes polytetrafluoroethylene dispersion resin; (3) The second binder solution is added to the second mixture in step (2) for a third mixing to obtain a third mixture; the solute of the second binder solution is the second binder, which includes any one or at least two of the following: PVP powder, PAA powder, PEG powder, CMC powder, PVDF powder, PVP adhesive, PAA adhesive, PEG adhesive, CMC adhesive or PVDF adhesive; (4) The third mixture in step (3) is subjected to a fourth mixing and heating treatment to obtain the fibrous fluffy powder. The heating treatment temperature is 60~120℃.

2. The preparation method according to claim 1, characterized in that, The mass ratio of the active material, conductive agent in step (1), the first adhesive in step (2), and the second adhesive in the solution of the second adhesive in step (3) is (92.5~97.5):(0.1~1):(0.9~5):1.

5.

3. The preparation method according to claim 1, characterized in that, The active material in step (1) includes a positive electrode active material or a negative electrode active material.

4. The preparation method according to claim 3, characterized in that, The positive electrode active material includes any one or a combination of at least two of LFP, NCM, or LiCoO3.

5. The preparation method according to claim 3, characterized in that, The negative electrode active material includes graphite and / or silicon-based materials.

6. The preparation method according to claim 5, characterized in that, The graphite includes natural graphite and / or artificial graphite.

7. The preparation method according to claim 5, characterized in that, The silicon-based materials include silicon-oxygen materials and / or silicon-carbon materials.

8. The preparation method according to claim 1, characterized in that, The conductive agent in step (1) includes any one or a combination of at least two of conductive carbon black, graphite, carbon nanofibers, single-walled carbon nanotubes, multi-walled carbon nanotubes, or graphene.

9. The preparation method according to claim 8, characterized in that, The conductive carbon black includes acetylene black and / or Ketjen black.

10. The preparation method according to claim 1, characterized in that, Step (1) The first mixing is carried out in a granulator, wherein the cutting speed of the granulator is 150~3000 rpm.

11. The preparation method according to claim 10, characterized in that, The cutting speed of the granulator is 800~1500 rpm.

12. The preparation method according to claim 1, characterized in that, Step (1) The first mixing is carried out in a granulator, wherein the scraper speed of the granulator is 50~300 rpm.

13. The preparation method according to claim 12, characterized in that, The scraper speed of the granulator is 150~300 rpm.

14. The preparation method according to claim 1, characterized in that, Step (1) The first mixing time is 1~60 min.

15. The preparation method according to claim 14, characterized in that, Step (1) The first mixing time is 10~20 min.

16. The preparation method according to claim 1, characterized in that, Step (2) The second mixing time is 1~20 min.

17. The preparation method according to claim 1, characterized in that, Step (2) The second mixing is carried out in a mixer.

18. The preparation method according to claim 17, characterized in that, In step (2), the rotation speed of the second mixing is 1500~45000 rpm.

19. The preparation method according to claim 18, characterized in that, In step (2), the rotation speed of the second mixing is 3000~30000 rpm.

20. The preparation method according to claim 1, characterized in that, Step (3) The solvent used in the second adhesive solution includes any one or a combination of at least two of the following: deionized water, N-methylpyrrolidone, volatile alcohol solvents or volatile silicone oil solvents.

21. The preparation method according to claim 1, characterized in that, In step (3), the mass fraction of the second adhesive in the second adhesive solution is 1-40%.

22. The preparation method according to claim 1, characterized in that, The revolution speed of the third mixture in step (3) is 15~30 rpm.

23. The preparation method according to claim 1, characterized in that, The solid content of the third mixed material in step (3) is 72-95%.

24. The preparation method according to claim 1, characterized in that, The third mixture in step (3) is then dried.

25. The preparation method according to claim 24, characterized in that, The drying temperature is 45~150℃.

26. The preparation method according to claim 24, characterized in that, The drying time is 0.5 to 3 hours.

27. The preparation method according to claim 1, characterized in that, The time for the fourth mixing in step (4) is 0.5 to 20 minutes.

28. The preparation method according to claim 1, characterized in that, The speed of the fourth mixing in step (4) is 1500~45000 rpm.

29. The preparation method according to claim 1, characterized in that, The speed of the fourth mixing in step (4) is 3000~30000 rpm.

30. A fibrous, fluffy powder, characterized in that, The fibrous fluffy powder is prepared by the method for preparing fibrous fluffy powder as described in any one of claims 1-29.

31. A lithium-ion battery, characterized in that, The lithium-ion battery includes an electrode film, which is prepared from the fibrous fluffy powder as described in claim 30.

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