Fibrous fluffy powder, preparation method therefor and lithium ion battery

Abstract

A fibrous fluffy powder, a preparation method therefor, and a lithium ion battery. The preparation method comprises: carrying out first mixing on an active material and a conductive agent to obtain a first mixture; adding a first binder to the first mixture for second mixing to obtain a second mixture; adding a second binder solution to the second mixture for third mixing to obtain a third mixture; and carrying out fourth mixing on the third mixture and then carrying out heating treatment to obtain fibrous fluffy powder.

Description

Fiberized fluffy powder, preparation method thereof, and lithium-ion battery

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on October 30, 2023, with application number 2023114295500. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The present application belongs to the field of lithium-ion batteries and relates to a fiberized fluffy powder, a preparation method thereof, and a lithium-ion battery. Background Art

[0003] Lithium-ion battery vehicles and energy storage are two major applications of lithium-ion batteries. Using new materials and processes to achieve high energy density and high power lithium-ion batteries is an important research and development direction.

[0004] In process development, dry electrode technology uses no or minimal solvents, offering cost advantages over wet processes. Furthermore, dry electrode technology allows for the production of thicker electrodes, freeing the electrode from being limited by the thickness of the coating.

[0005] In dry electrode preparation, fiberization after dry powder mixing is an important process step. In related technologies, high-speed mixing and airflow mixing are mainly used to achieve dry electrode powder fiberization through a single crushing process. This requires the use of a high shear rate in the mixing equipment, which not only causes great wear and tear on the equipment and high energy consumption, but more importantly, the high shear strength damages the structure of the active material, affecting the electrochemical performance of lithium-ion batteries. However, a slightly lower shear strength makes it difficult to achieve sufficient fiberization and cannot meet the requirements of dry electrode preparation. Technical issues

[0006] The embodiments of the present application provide a fiberized fluffy powder, a preparation method thereof, and a lithium-ion battery to improve the fiberization degree of the powder. Technical Solutions

[0007] In a first aspect, an embodiment of the present application provides a method for preparing a fiberized fluffy powder, the method comprising:

[0008] performing a first mixing of the active material and the conductive agent to obtain a first mixed material;

[0009] adding a first binder to the first mixture for second mixing to obtain a second mixture;

[0010] adding a second binder solution to the second mixed material for a third mixing to obtain a third mixed material;

[0011] The third mixed material is subjected to a fourth mixing and then heating treatment to obtain the fiberized fluffy powder.

[0012] In a second aspect, an embodiment of the present application provides a fiberized fluffy powder, which is prepared by the method for preparing the fiberized fluffy powder as described in the first aspect above.

[0013] In a third aspect, an embodiment of the present application provides a lithium-ion battery, wherein the lithium-ion battery includes an electrode membrane, and the electrode membrane is prepared from the fiberized fluffy powder as described in the second aspect above. Beneficial effects

[0014] Beneficial effects of this application:

[0015] (1) The fibrous fluffy powder prepared in this application has good film-forming properties and good strength, which can reach 0.45 MPa;

[0016] (2) The preparation method of the fiberized fluffy powder of the present application is simple and easy, and can improve the fiberization degree of the powder;

[0017] (3) The preparation process of the fiberized fluffy powder of the present application has low requirements on equipment, which can reduce equipment wear and energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG1 is a schematic flow chart of a method for preparing a fiberized fluffy powder provided in an embodiment of the present application.

[0019] FIG2 is an SEM image of the fiberized fluffy powder in Example 1 of the present application. Modes for Carrying Out the Invention

[0020] Referring to FIG1 , an embodiment of the present application provides a method for preparing a fiberized fluffy powder, the method comprising:

[0021] S110, performing a first mixing of the active material and the conductive agent to obtain a first mixed material;

[0022] S120, adding a first binder to the first mixture for second mixing to obtain a second mixture;

[0023] S130, adding the second binder solution to the second mixture for third mixing to obtain a third mixture;

[0024] S140, performing a fourth post-mixing heating treatment on the third mixed material to obtain the fiberized fluffy powder.

[0025] In the embodiment of the present application, the active material and the conductive agent are first mixed in S110 to increase the conductivity inside the electrode. In the present application, the first binder has a fiberizable property. The binder is added twice in S120 and S130 for mixing to facilitate the dispersion of different binders, so that the powder friction coefficient inside the powder at different times is different, so that the unfiberized part of the first binder is fiberized, and the interaction between the second binder and the first binder is achieved. In S140, the third mixture is further mixed for the fourth time to further enhance the fiberization of the first binder. The powder after the fourth mixing in the present application is heated. After the addition treatment, the powder shows obvious spider web drawing, and most of the binders have achieved a high degree of fiberization.

[0026] The preparation method of the present application is simple and easy, improves the fiberization degree of the powder, reduces the rotation speed of the high-speed mixing equipment, reduces the requirements for the equipment, and reduces the wear and energy consumption of the equipment. The fiberized fluffy powder prepared by the preparation method of the present application has good film-forming properties, better improves the strength of the membrane, and avoids powder loss of the membrane.

[0027] In one embodiment, the mass ratio of the active material, the conductive agent, the first binder and the second binder in the second binder solution 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 numerical range are also applicable.

[0028] Preferably, the active material includes a positive electrode active material or a negative electrode active material.

[0029] Preferably, the negative electrode active material includes graphite and / or silicon-based materials.

[0030] Preferably, the graphite includes natural graphite and / or artificial graphite.

[0031] Preferably, the silicon-based material includes silicon-oxygen material and / or silicon-carbon material.

[0032] Preferably, the positive electrode active material includes any one of LFP, NCM or LiCoO3 or a combination of at least two of them, 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.

[0033] In one embodiment, the conductive agent in S110 includes any one of conductive carbon black, acetylene black, Ketjen black, graphite, nanocarbon fibers, single-walled carbon nanotubes, multi-walled carbon nanotubes or graphene, or a combination of at least two of them, wherein typical but non-limiting examples of the combination include: a combination of conductive carbon black and acetylene black, a combination of Ketjen black and graphite, a combination of nanocarbon fibers 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.

[0034] In one embodiment, the first mixing in S110 is carried out in a granulator, and the cutter speed of the granulator is 150 to 3000 rpm, wherein the cutter 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 the numerical range are also applicable, preferably 800 to 1500 rpm.

[0035] In one embodiment, the first mixing in S110 is carried out in a granulator, and 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 the numerical range are also applicable, preferably 150 to 300 rpm.

[0036] In one embodiment, the first mixing time is 1 to 60 min, wherein the time can be 1 min, 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min or 60 min, etc., but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, preferably 10 to 20 min.

[0037] In one embodiment, the first binder includes polytetrafluoroethylene dispersion resin.

[0038] This application uses polytetrafluoroethylene (PTFE) dispersion resin as the first binder. PTFE dispersion resin has fiberizing properties. Under certain shear strengths or temperatures, its original crystal structure undergoes a phase transition, transforming from primary particles into filaments. This application first mixes the first binder to achieve fiberization, changing the surface state of the first binder, and then mixes the second binder, facilitating interaction between the second binder and the first binder.

[0039] In one embodiment, the time for the second mixing in S120 is 1 to 20 minutes, where 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, and other unlisted values ​​within the numerical range are also applicable.

[0040] Preferably, the second mixing is performed in a mixer.

[0041] Preferably, the rotation speed of the second mixing is 1500-45000 rpm, wherein the rotation 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, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, preferably 3000-30000 rpm.

[0042] In one embodiment, the second mixing rotation speed matches the size of the material cylinder and the size of the dispersing blade, and needs to satisfy that the linear velocity at the middle position of the blade is greater than 30 m / s.

[0043] In one embodiment, the solute of the second binder solution is a second binder, and the second binder includes any one of PVP (polyvinyl pyrrolidone) powder, PAA (polyacrylic acid) powder, PEG (polyethylene glycol) powder, CMC (sodium carboxymethyl cellulose) powder, PVDF (polyvinylidene fluoride) powder, PVP (polyvinyl pyrrolidone) emulsion, PAA (polyacrylic acid) emulsion, PEG (polyethylene glycol) emulsion, CMC (sodium carboxymethyl cellulose) emulsion or PVDF (polyvinylidene fluoride) emulsion, or a combination of at least two thereof, wherein typical but non-limiting examples of the combination include: a combination of PVP powder and PAA powder, a combination of PEG powder and CMC powder, a combination of PVP emulsion and PAA emulsion, a combination of PEG emulsion and CMC emulsion, or a combination of PVDF emulsion and PAA powder, etc.

[0044] In one embodiment, the solvent used in the second binder solution includes any one of deionized water, N-methylpyrrolidone, a volatile alcohol solvent, or a volatile silicone oil solvent, or a combination of at least two of them, wherein typical but non-limiting examples of the combination include: a combination of deionized water and a volatile alcohol solvent, or a combination of N-methylpyrrolidone and a volatile silicone oil solvent.

[0045] The purpose of selecting the second binder solution in this application is to facilitate better dispersion and dissolution of the second binder to stretch the macromolecular chains. Selecting the type of second binder can better improve the quality of the electrode and the first effect of the battery and other electrochemical properties.

[0046] In one embodiment, the mass fraction of the second binder in the second binder 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 the numerical range are also applicable.

[0047] In one embodiment, the revolution speed of the third mixing 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, and other unlisted values ​​within the numerical range are also applicable.

[0048] In one embodiment, the solid content of the third mixed material is 72% to 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 the numerical range are also applicable.

[0049] In one embodiment, the third mixing is followed by drying. In one embodiment, 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. Other values ​​not listed in the numerical range are also applicable.

[0050] In one embodiment, 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 values ​​not listed within the numerical range are also applicable.

[0051] Preferably, continue to dry naturally after drying.

[0052] Preferably, the drying equipment is a blast oven, which can dry the powder and also help increase fiberization.

[0053] In one embodiment, the fourth mixing time 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, and other unlisted values ​​within the numerical range are also applicable.

[0054] In one embodiment, the speed of the fourth mixing is 1500-45000 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, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, preferably 3000-30000 rpm.

[0055] In one embodiment, the rotation speed of the fourth mixing device 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 must be greater than 30 m / s.

[0056] In one embodiment, the fourth mixing is performed by a high-speed shear mixing method, and an ultra-fluffy and soft powder is obtained after the fourth mixing.

[0057] In one embodiment, the temperature of the heating treatment is 60-120°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, and other unlisted values ​​within the numerical range are also applicable.

[0058] In one embodiment, the fourth mixed powder is subjected to a heat treatment, and after the treatment, the powder exhibits obvious spider web-like filaments, and most of the binder achieves a high degree of fiberization.

[0059] The fibrous fluffy powder prepared in the present application has good film-forming properties and good strength, the strength of which can reach 0.45Mpa; the preparation method of the fibrous fluffy powder in the present application is simple and easy, and can improve the fiberization degree of the powder; the preparation process of the fibrous fluffy powder in the present application has low requirements for equipment, which can reduce equipment wear and energy consumption.

[0060] An embodiment of the present application further provides a fibrous fluffy powder, which is prepared by the fibrous fluffy powder preparation method as described above.

[0061] An embodiment of the present application further provides a lithium-ion battery, which includes an electrode membrane, and the electrode membrane is prepared from the fiberized fluffy powder as described above.

[0062] Example 1

[0063] This embodiment provides a method for preparing a fiberized fluffy powder. The raw materials are: artificial graphite, conductive carbon black, polytetrafluoroethylene powder, and PVP powder-PVP powder in deionized water in a mass ratio of 95:1:2.5:1.5. The specific preparation method includes the following steps:

[0064] (1) artificial graphite and conductive carbon black are first mixed to obtain a first mixture, wherein the cutter speed of the first mixing is 1200 rpm, the scraper speed is 220 rpm, and the time is 15 minutes;

[0065] (2) adding polytetrafluoroethylene dispersion resin to the first mixture in step (1) for a second mixing to obtain a second mixture, wherein the second mixing speed is 25000 rpm and the time is 15 minutes;

[0066] (3) adding a second binder solution prepared by PVP powder-deionized water with a mass fraction of 20% to the second mixed material in step (2) for a third mixing to obtain a third mixed material, wherein the speed of the third mixing 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 forced air drying at a temperature of 85° C. and a drying time of 30 min;

[0067] (4) The third mixture in step (3) is subjected to a fourth mixing process at a speed of 20,000 rpm for 10 minutes and then heated at 85° C. to obtain the fiberized fluffy powder.

[0068] The SEM image of the fibrous fluffy powder obtained in this example is shown in Figure 2. Example 2

[0069] This embodiment provides a method for preparing a fiberized fluffy powder. The raw materials are: natural graphite, Ketjen black, polytetrafluoroethylene dispersion resin, and PAA powder-PAA powder in ethanol solution. The mass ratio of the PAA powder is 97.5:0.1:0.9:1.5. The specific preparation method includes the following steps:

[0070] (1) mixing natural graphite and Ketjen black to obtain a first mixture, wherein the first mixing has a cutter speed of 150 rpm, a scraper speed of 50 rpm, and a mixing time of 60 min;

[0071] (2) adding polytetrafluoroethylene to the first mixture in step (1) for a second mixing to obtain a second mixture, wherein the second mixing speed is 1500 rpm and the time is 20 minutes;

[0072] (3) adding a 1% by mass PAA powder-ethanol solution to the second mixed material in step (2) for a third mixing to obtain a third mixed material. The speed of the third mixing is 25 rpm, and 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. and a drying time of 3 h.

[0073] (4) The third mixture in step (3) is subjected to a fourth mixing process at a speed of 1500 rpm for 20 minutes and then heated at 60° C. to obtain the fiberized fluffy powder.

[0074] Example 3

[0075] This embodiment provides a method for preparing a fiberized fluffy powder. The raw materials are: LiCoO3, single-walled carbon nanotubes, polytetrafluoroethylene dispersion resin, and PVDF powder-PVDF powder in N-methylpyrrolidone solution in a mass ratio of 92.5:1:5:1.5. The specific preparation method includes the following steps:

[0076] (1) performing a first mixing of LiCoO3 and single-walled carbon nanotubes to obtain a first mixture, wherein the first mixing is performed at a cutter speed of 3000 rpm, a scraper speed of 300 rpm, and a mixing time of 1 minute;

[0077] (2) adding polytetrafluoroethylene dispersion resin to the first mixture in step (1) for a second mixing to obtain a second mixture, wherein the second mixing speed is 45,000 rpm and the time is 1 minute;

[0078] (3) adding a 40% by mass PVDF powder-N-methylpyrrolidone solution to the second mixture of step (2) for a third mixing to obtain a third mixture, wherein the speed of the third mixing is 30 rpm, and the solid content of the material after the third mixing is 95%. The third mixture is dried by forced air drying at a temperature of 150° C. and a drying time of 30 min;

[0079] (4) The third mixture in step (3) is subjected to a fourth mixing process at a speed of 45,000 rpm for 0.5 min and then heated at 120° C. to obtain the fiberized fluffy powder.

[0080] Example 4

[0081] In this embodiment, except that the PVP powder in step (3) is replaced by SBR emulsion, other conditions are the same as those in Example 1.

[0082] Example 5

[0083] In this embodiment, except that the PVP powder-deionized water with a mass fraction of 20% in step (3) is replaced by PVP powder, other conditions are the same as those in Example 1.

[0084] Example 6

[0085] In this embodiment, except that the temperature of the heating treatment in step (4) is replaced with 30° C., other conditions are the same as those in embodiment 1.

[0086] Example 7

[0087] In this embodiment, except that the temperature of the heating treatment in step (4) is replaced with 140° C., other conditions are the same as those in embodiment 1.

[0088] Comparative Example 1

[0089] Except for not performing step (2), other conditions in this comparative example are the same as those in Example 1.

[0090] Comparative Example 2

[0091] Except for not performing step (3), other conditions in this comparative example are the same as those in Example 1.

[0092] Comparative Example 3

[0093] Except for not performing step (4), other conditions in this comparative example are the same as those in Example 1.

[0094] The fiberized fluffy powders prepared in Examples 1-2, Examples 4-7 and Comparative Examples 1-3 were prepared as negative electrode membranes, and the fiberized fluffy powders prepared in Example 3 were prepared as positive electrode membranes. The method for preparing negative electrode membranes from the fiberized fluffy powders in Examples 1-2, Examples 4-7 and Comparative Examples 1-3 was as follows: first, the powders were fiberized and then rolled into membranes.

[0095] The positive electrode diaphragms or negative electrode diaphragms prepared in Examples 1-7 and Comparative Examples 1-3 were tested for electrode diaphragm strength. The specific test method for tensile strength was as follows: a universal tensile testing machine (50N range dynamometer, cutting standard size samples: length * width = 100mm * 20mm, gauge length 50mm) was used to test the electrode diaphragm strength.

[0096] The test results of the membrane strength of Examples 1-7 and Comparative Examples 1-3 of the present application are shown in Table 1.

[0097] Table 1

[0098] From the above table, it can be seen that the fiberization is greatly improved after secondary fiberization. After compounding with other binders, the improvement of fiberization is more obvious, and the strength of the film-forming membrane is better.

[0099] Comparison between Example 1 and Example 4 shows that after the PVP powder in step (3) is replaced with SBR (styrene-butadiene rubber) emulsion, the film-forming property of the powder after fiberization becomes worse, indicating that the film strength is related to the type of compound binder. Direct addition of SBR emulsion does not increase the fiberization effect. The type of compound binder has a certain influence on the fiberization effect.

[0100] Comparison between Example 1 and Example 5 shows that the PVP powder-deionized water with a mass fraction of 20% in step (3) is replaced by PVP powder, indicating that the secondary fiberization effect can be achieved only after the composite binder is dispersed under the influence of the solution, and the direct addition of dry powder does not increase the fiberization effect, that is, the improvement of the membrane strength is directly related to the secondary fiberization process;

[0101] Comparison between 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 processing of the membrane, and the corresponding membrane strength is lower than the optimal temperature range;

[0102] Comparison of Example 1 with Comparative Examples 1-3 shows that other powder preparation methods cannot achieve the dry film processing strength of this method.

Claims

1. A method for preparing a fibrous fluffy powder, the preparation method comprising: Performing a first mixing of the active material and the conductive agent to obtain a first mixed material; adding a first binder to the first mixed material for second mixing to obtain a second mixed material; adding a second binder solution to the second mixed material for a third mixing to obtain a third mixed material; The third mixed material is subjected to a fourth post-mixing heating treatment to obtain the fiberized fluffy powder.

2. The preparation method according to claim 1, wherein The mass ratio of the active material, the conductive agent, the first binder and the second binder in the second binder solution is (92.5-97.5):(0.1-1):(0.9-5):1.5; Preferably, the active material comprises a positive electrode active material or a negative electrode active material; Preferably, the positive electrode active material includes any one of LFP, NCM or LiCoO3 or a combination of at least two thereof; Preferably, the negative electrode active material comprises graphite and / or silicon-based materials; Preferably, the graphite comprises natural graphite and / or artificial graphite; Preferably, the silicon-based material includes silicon-oxygen material and / or silicon-carbon material; Preferably, the conductive agent includes any one of conductive carbon black, acetylene black, Ketjen black, graphite, nano-carbon fiber, single-walled carbon nanotube, multi-walled carbon nanotube or graphene, or a combination of at least two thereof.

3. The preparation method according to claim 1 or 2, wherein The first mixing is performed in a granulator, and the cutter speed of the granulator is 150 to 3000 rpm, preferably 800 to 1500 rpm; Preferably, the first mixing is performed in a granulator, and the scraper speed of the granulator is 50 to 300 rpm, preferably 150 to 300 rpm; Preferably, the first mixing time is 1 to 60 min, preferably 10 to 20 min.

4. The preparation method according to any one of claims 1 to 3, wherein: The first binder includes polytetrafluoroethylene dispersion resin.

5. The preparation method according to any one of claims 1 to 4, wherein: The second mixing time is 1 to 20 minutes; Preferably, the second mixing is carried out in a mixer; Preferably, the second mixing speed is 1500-45000 rpm, preferably 3000-30000 rpm.

6. The preparation method according to any one of claims 1 to 5, wherein: The solute of the second binder solution is a second binder, and the second binder includes any one of PVP powder, PAA powder, PEG powder, CMC powder, PVDF powder, PVP emulsion, PAA emulsion, PEG emulsion, CMC emulsion or PVDF emulsion, or a combination of at least two thereof; Preferably, the solvent used in the second binder solution includes any one of deionized water, N-methylpyrrolidone, a volatile alcohol solvent or a volatile silicone oil solvent, or a combination of at least two thereof; Preferably, the mass fraction of the second binder in the second binder solution is 1-40%.

7. The preparation method according to any one of claims 1 to 6, wherein: The revolution speed of the third mixing is 15-30 rpm; Preferably, the solid content of the material after the third mixing is 72-95%; Preferably, the third mixing is followed by drying; Preferably, the drying temperature is 45 to 150°C; Preferably, the drying time is 0.5 to 3 hours.

8. The preparation method according to any one of claims 1 to 7, wherein: The fourth mixing time is 0.5 to 20 minutes; Preferably, the speed of the fourth mixing is 1500-45000 rpm, preferably 3000-30000 rpm; Preferably, the temperature of the heating treatment is 60-120°C.

9. A fibrous fluffy powder, wherein the fibrous fluffy powder is prepared by the method for preparing the fibrous fluffy powder according to any one of claims 1 to 8.

10. A lithium-ion battery, comprising an electrode membrane, wherein the electrode membrane is prepared from the fiberized fluffy powder according to claim 9.

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