High-load electrode, preparation method thereof and application of high-load electrode in battery

Abstract

The invention discloses a high-load electrode, a preparation method thereof and application of the high-load electrode in a battery, the high-load electrode comprises a carbon nanotube, a porous current collector and an active material, and the mass ratio of active particles to the carbon nanotube is 95: 5-99.5: 0.5; the active material comprises a positive active material and a negative active material. According to the invention, no additional binder needs to be added, adverse effects caused by chemical side reactions are avoided, rapid transmission of electrons is effectively realized, the gas production risk in the battery circulation process is reduced, and the safety and high efficiency of the battery are ensured; the surface loading capacity of the electrode piece is high, the electrode piece is tightly coated, the charge seepage network is strong, and the cracking and falling phenomena of the electrode piece are avoided; and abundant pore channels are formed to promote electrolyte permeation and ion transmission, so that the quick charge characteristic of the high-specific-energy battery is realized.

Description

Technical Field

[0001] The present invention relates to an electrode material, a preparation method thereof and an application thereof, and particularly to a high-loading electrode, a preparation method thereof and an application thereof in a battery. Background Art

[0002] In recent years, fast-charging lithium-ion batteries have received extensive attention due to their applications in energy storage fields such as electric vehicles and power grids. However, when lithium-ion batteries are fast-charged, the electrode materials prepared by traditional coating methods may not be able to maintain the optimal state, and are extremely prone to cracking, contact failure, etc. in a short time, resulting in battery attenuation or even thermal runaway. When manufacturing high-energy-density lithium-ion batteries, due to the defect that the coating method cannot tightly connect the active material to the current collector, cracking or even falling off is extremely likely to occur during the drying process of the electrode sheet, directly causing irreversible loss of materials, wasting resources, and the rate performance and energy density of existing lithium-ion battery and sodium-ion battery materials are insufficient. Summary of the Invention

[0003] Object of the Invention: The object of the present invention is to provide a high-loading electrode with a high areal loading, high rate performance and high energy density; another object of the present invention is to provide a preparation method of a high-loading electrode that effectively shortens the charge transfer distance inside the battery and significantly improves the specific energy; the present invention also provides an application of a high-loading electrode in a battery.

[0004] Technical Solution: A high-loading electrode described in the present invention includes carbon nanotubes, a porous current collector and an active material, and the mass ratio of the active particles to the carbon nanotubes is 95:5 to 99.5:0.5; the active material includes a positive electrode active material and a negative electrode active material.

[0005] Further, the porous current collector is one or more of porous aluminum foil, copper foil, polymer and their composite foils, and the pore size is 5-20 μm; if the pore size of the current collector is too large, the active particles and carbon nanotubes will pass through the porous current collector and cannot be tightly adsorbed, resulting in material waste.

[0006] Further, the active material is one or more of lithium iron phosphate, lithium cobaltate, nickel cobalt manganese ternary, sodium vanadium phosphate, graphite, silicon-based, lithium titanate, soft carbon, hard carbon, tin-based material, titanium-based material.

[0007] Further, the carbon nanotubes are one or more of short-range single-walled carbon nanotubes, long-range single-walled carbon nanotubes, short-range multi-walled carbon nanotubes, long-range multi-walled carbon nanotubes.

[0008] A preparation method of a high-loading electrode described in the present invention includes the following steps:

[0009] (1) Grind, screen, and dry the active material to obtain uniform active particles;

[0010] (2) Dissolve carbon nanotubes and a dispersant in a solvent to obtain a carbon nanotube dispersion, and then premix the active particles in step (1) with the carbon nanotube dispersion uniformly to obtain a homogeneous solution;

[0011] (3) Perform intermittent ultrasonic stirring treatment on the homogeneous solution to obtain a mixed solution;

[0012] (4) Perform vacuum filtration and washing on the mixed solution until all the material particles in the solution are adsorbed onto the porous current collector to obtain an electrode sheet;

[0013] (5) Perform vacuum drying, rolling, and cutting on the electrode sheet to obtain a high-loading electrode sheet.

[0014] Further, in the carbon nanotube dispersion in step (2), the mass fraction of carbon nanotubes is 0.1 - 0.4 wt%, the mass fraction of sodium carboxymethyl cellulose dispersant is 0.15 - 0.6 wt%, and the balance is the solvent; the solvent is ultrapure deionized water or N-methylpyrrolidone; the mass ratio of the active particles to the carbon nanotubes is 95:5 - 99.5:0.5.

[0015] Further, the drying temperature in steps (1) and (5) is 80 - 120 °C, and the drying time is 8 - 12 h.

[0016] Further, in step (2), a magnetic stirrer is used for premixing, the rotation speed is 800 - 1000 rpm, and the stirring time is 30 - 60 min; in step (3), the intermittent ultrasonic stirring treatment time is 30 - 60 min, the ultrasonic power is 200 - 300 W, and the stirring rotation speed is 400 - 600 rpm.

[0017] Further, the vacuum degree of vacuum filtration in step (4) reaches 0.01 - 0.1 MPa, and the filtration time is 3 - 6 h; deionized water is added for washing 3 - 4 times. When the vacuum degree of filtration increases, the active material will be tightly adsorbed on the porous current collector, and it is easy to cause blockage phenomenon in a short time, making it impossible to fabricate the electrode material normally.

[0018] The present invention also includes an application of the high-loading electrode in sodium-ion batteries and lithium-ion batteries.

[0019] Principle of the present invention: The high-loading electrode is composed of an active material, carbon nanotubes, and a porous current collector. Through the suction filtration process, the active material and carbon nanotubes are evenly adsorbed onto the porous current collector. The carbon nanotubes form a three-dimensional network crosslinking and cooperate with the porous current collector, tightly winding between the active particles, effectively connecting the porous current collector and the active material. Among them, the carbon nanotube (CNTs) cocoon binding technology is utilized. The carbon nanotubes have high toughness and a large aspect ratio to establish an excellent conductive network and a "cocoon" electrode structure, ensuring charge transfer and beneficial mechanical properties while achieving a high loading of active substances. The crosslinking network effect of carbon nanotubes is realized by the vacuum suction filtration method, establishing the "cocoon" binding of active particles and a "self-supporting" crosslinked conductive network, effectively alleviating the volume expansion and contraction problems of active particles during the charge and discharge process of the battery. The high-loading electrode prepared by the vacuum suction filtration method does not require a binder. The active particles of the electrode material are bound by the three-dimensional conductive network formed by carbon nanotubes, significantly improving the energy density of lithium-ion batteries / sodium-ion batteries, enhancing the high-rate charge and discharge performance of the battery, and also expanding the application fields of lithium-ion batteries and sodium-ion batteries.

[0020] Beneficial effects: Compared with the prior art, the present invention has the following significant features:

[0021] 1. No additional binder is required, avoiding the adverse effects caused by chemical side reactions, effectively realizing the rapid transmission of electrons, reducing the gas generation risk during battery cycling, and ensuring the safety and high efficiency of the battery;

[0022] 2. The electrode has a high areal loading, is tightly coated, and has a strong charge percolation network, avoiding the phenomenon of electrode cracking and shedding;

[0023] 3. Abundant pores are formed to promote electrolyte penetration and ion transport, realizing the fast charging characteristics of high specific energy batteries. Description of the drawings

[0024] Figure 1 is the flow chart of the preparation method of the high-loading electrode of the present invention;

[0025] Figure 2 is the cycle diagram of the sodium-ion battery with the high-loading sodium vanadium phosphate electrode in Example 1 of the present invention;

[0026] Figure 3 is the voltage-specific capacity curve of the sodium-ion battery with the high-loading sodium vanadium phosphate electrode in Example 1 of the present invention;

[0027] Figure 4 is the cycle diagram of the lithium-ion battery with the high-loading graphite electrode in Example 4 of the present invention;

[0028] Figure 5 is the XRD comparison diagram of the high-loading graphite electrode in Example 4 of the present invention;

[0029] Figure 6 This is a SEM picture of the high-load electrode graphite cocoon binding in Example 4 of the present invention. DETAILED DESCRIPTION

[0030] In the following examples, the materials, reagents, etc. used, unless otherwise specified, can be obtained from commercial sources. The carbon nanotube slurry is made from OCSiAl, product code 02HO17, wherein the mass fraction of carbon nanotubes is 0.4wt%, the average outer diameter of carbon nanotubes is 1.6nm, and the length is greater than 5μm, and the mass fraction of sodium carboxymethyl cellulose dispersant is 0.6wt%. Experimental methods without specific conditions in the examples are usually carried out under conventional conditions or under conditions recommended by the manufacturer.

[0031] Example 1

[0032] Sodium Vanadium Phosphate 3 V 2 (PO 4 ) 3 It belongs to the sodium ion superconductor (NASICON) material, which has an open three-dimensional ion migration channel that is conducive to improving the diffusion of sodium ions. 3 V 2 (PO 4 ) 3 As a positive electrode material for batteries, it has ideal specific capacity, voltage platform and cycle stability. However, the insufficient electron transmission of the material itself limits the cycle stability and rate performance of sodium ion batteries. The present invention utilizes the "cocoon binding technology" of carbon nanotubes and the synergistic effect of porous current collectors to improve the charge transmission capacity of sodium vanadium phosphate, improve the intrinsic electronic conductivity of the material, effectively improve the problem of uneven stress distribution of the material, and achieve the characteristics of high load and excellent cycle stability.

[0033] The method for preparing a high-load electrode using a sodium vanadium phosphate positive electrode and a porous aluminum current collector comprises the following steps:

[0034] (1) The sodium vanadium phosphate material was ground for 30 minutes, sieved through a 200-mesh standard test sieve to obtain sodium vanadium phosphate positive electrode active particles with uniform particle size, fully mixed to prevent particle agglomeration, and placed in a vacuum drying oven for heating and drying at a drying temperature of 120° C. for 8 hours to remove moisture from the active particles.

[0035] (2) Weigh 833.49 mg of carbon nanotube slurry and dissolve it in 30 ml of ultrapure water to obtain a carbon nanotube dispersion.

[0036] (3) Weigh 330.06 mg of sodium vanadium phosphate cathode active particles and add them to the carbon nanotube dispersion obtained in step (1). Stir and mix them in a magnetic stirrer. Set the stirring speed to 800 rpm and the stirring time to 30 min to obtain a homogeneous solution. Place the homogeneous solution in an ultrasonic machine and perform intermittent ultrasonic treatment for 30 min. The ultrasonic power is 200 W, the ultrasonic working time is 3 s, and the rest time is 3 s. During ultrasonic treatment, the stirring speed is 400 rpm and the stirring time is 30 min until the solution is fully mixed and stirred evenly. Further ultrasonic and stirring treatment is carried out to prevent stratification.

[0037] (4) According to the hydrophilic characteristics and particle size of the materials, assemble a suction filtration device using a porous aluminum current collector with a pore size of 5 μm. Place the ultrasonicated mixed solution in the suction filtration device and filter the solution using the adsorption effect of a vacuum pump. The sodium vanadium phosphate active particles and carbon nanotubes are adsorbed on the porous aluminum current collector. When the electrode plate is slightly exposed during suction filtration, add deionized water for washing, repeat 3 times. The suction filtration time is 3 h and the vacuum degree of the suction filtration device is 0.1 MPa.

[0038] (5) Dry the obtained sodium vanadium phosphate cathode plate in a vacuum drying oven. The drying temperature is 120 °C and the drying time is 8 h. After rolling, cut it to obtain a sodium vanadium phosphate cathode plate with a high compaction density.

[0039] Press the sodium vanadium phosphate cathode plate and measure its weight using an electronic scale. The areal density of the prepared sodium vanadium phosphate cathode plate is 20.41 mg / cm 2 。

[0040] Application Example 1

[0041] Assemble the above-prepared sodium vanadium phosphate cathode plate, 500-μm sodium sheet, and glass fiber separator into a 2032-type button battery. The electrolyte is a solvent mixture of 1.0 M NaPF6 dissolved in ethylene carbonate (EC): dimethyl carbonate (DMC): ethyl methyl carbonate (EMC) = 1:1:1 Vol%. Test conditions for the cycling performance: at 25 °C, step 1: leave it standing for 2 h; step 2: constant current charge at 0.1 C until the cut-off voltage of 4.0 V; step 3: leave it standing for 2 min; step 4: constant current discharge at 0.1 C until the cut-off voltage of 2.0 V. Thus, cycle steps 1-4 until the activation step is completed. After the activation is completed, start constant current charging at 0.2 C to 4.0 V and discharge at 0.2 C to 2.0 V, and always maintain the cycle until the battery fails or decays to less than 80% of the initial capacity.

[0042] Figure 2 It is a schematic diagram of the cycle of a sodium-ion battery with a high-loading electrode of sodium vanadium phosphate in Example 1.

[0043] Figure 3Voltage-specific capacity curve of the sodium-ion battery with a high-loading electrode of sodium vanadate phosphate in Example 1.

[0044] Example 2

[0045] Replace sodium vanadate phosphate in Example 1 with lithium cobaltate, and use a high-loading electrode with a porous aluminum current collector. The preparation method includes the following steps:

[0046] (1) Grind the lithium cobaltate material for 30 min, sieve it through a standard test sieve with a mesh size of 200, and obtain lithium cobaltate positive active particles with uniform particle size. Mix them well to prevent particle agglomeration, and place them in a vacuum drying oven for heating and drying at a temperature of 90 °C for 10 h to remove the moisture in the active particles.

[0047] (2) Dissolve 331.72 mg of carbon nanotube slurry in 20 ml of ultrapure water to obtain a carbon nanotube dispersion.

[0048] (3) According to the weight ratio of carbon nanotubes to lithium cobaltate positive active particles of 0.5:99.5, add 264.05 mg of lithium cobaltate positive particles to the carbon nanotube dispersion, stir and mix in a magnetic stirrer, set the stirring speed to 850 rpm, and stir for 40 min to obtain a homogeneous solution; place the homogeneous solution in an ultrasonic machine for intermittent ultrasonic treatment for 40 min, with an ultrasonic power of 210 W, an ultrasonic working time of 3 s, a rest time of 3 s, an ultrasonic stirring speed of 500 rpm, and a stirring time of 40 min until the solution is fully mixed and stirred evenly. Further ultrasonic and stirring treatment is carried out to prevent stratification.

[0049] (4) According to the hydrophilic characteristics and particle size of the materials, assemble a suction filtration device using a porous aluminum current collector with a pore size of 15 μm. Place the ultrasonicated mixed solution in the suction filtration device, filter the solution using the adsorption effect of a vacuum pump, and the lithium cobaltate active particles and carbon nanotubes are adsorbed on the porous aluminum current collector. When the electrode plate is slightly exposed during suction filtration, add deionized water for washing, repeat 3 times, the suction filtration time is 3 h, and the vacuum degree of the suction filtration device is 0.05 MPa.

[0050] (5) Dry the obtained lithium cobaltate positive electrode plate in a vacuum drying oven at a drying temperature of 90 °C for 10 h, roll it and then cut it to obtain a lithium cobaltate positive electrode plate with a high compaction density.

[0051] Take the lithium cobaltate positive electrode plate and press it into a tablet, measure and weigh it using an electronic scale. The surface density of the prepared lithium cobaltate positive electrode plate is 19.3 mg / cm 2 .

[0052] Example 3

[0053] Replace sodium vanadate phosphate in Example 1 with lithium iron phosphate, and use a porous aluminum current collector to prepare a high-loading electrode. The preparation method includes the following steps:

[0054] (1) Grind the lithium iron phosphate material for 30 min, sieve it through a standard test sieve with a mesh size of 200, and obtain uniformly sized lithium iron phosphate cathode active particles. Mix them thoroughly to prevent particle agglomeration, and place them in a vacuum drying oven for heating and drying at a temperature of 100 °C for 9 h to remove the moisture in the active particles.

[0055] (2) Dissolve 3.474 g of carbon nanotube slurry in 50 ml of ultrapure water to obtain a carbon nanotube dispersion.

[0056] (3) The carbon nanotubes and lithium iron phosphate cathode active particles are mixed in a weight ratio of 5:95. Add 264.05 mg of lithium iron phosphate cathode particles to the carbon nanotube dispersion and stir and mix them in a magnetic stirrer. Set the stirring speed to 900 rpm and the stirring time to 50 min to obtain a homogeneous solution; place the homogeneous solution in an ultrasonic machine for intermittent ultrasonic treatment for 50 min, with an ultrasonic power of 300 W, an ultrasonic working time of 3 s, a rest time of 3 s, an ultrasonic stirring speed of 500 rpm, and a stirring time of 50 min until the solution is fully mixed and stirred evenly. Further ultrasonic and stirring treatments are carried out to prevent layering.

[0057] (4) According to the hydrophilic characteristics and particle size of the material, assemble a suction filtration device using a porous aluminum current collector with a pore size of 10 μm. Place the ultrasonicated mixed solution in the suction filtration device and filter the solution using the adsorption effect of a vacuum pump. The lithium iron phosphate active particles and carbon nanotubes are adsorbed on the porous aluminum current collector. When the electrode plate is slightly exposed, add deionized water for washing, repeat 3 times, with a suction filtration time of 4 h and a vacuum degree of the suction filtration device of 0.08 MPa.

[0058] (5) Dry the obtained lithium iron phosphate cathode plate in a vacuum drying oven at a drying temperature of 80 °C for 9 h, roll press it, and then cut it to obtain a lithium iron phosphate cathode plate with a high tap density.

[0059] Take the lithium iron phosphate cathode plate and press it into a tablet, measure and weigh it using an electronic balance to obtain the areal density of the electrode plate. The areal density of the prepared lithium iron phosphate cathode plate is 18.4 mg / cm 2 .

[0060] Example 4

[0061] A preparation method for a high-loading electrode using a graphite anode and a porous copper current collector includes the following steps:

[0062] (1) Grind the graphite for 30 min and then sieve it through a 300-mesh standard test sieve to obtain graphite negative active particles with uniform particle size. Place them in a vacuum drying oven for heating and drying at a temperature of 80 °C for 12 h to remove the moisture in the particles.

[0063] (2) Dissolve 833.49 mg of carbon nanotube slurry in 30 ml of ultrapure water to obtain a carbon nanotube dispersion.

[0064] (3) The carbon nanotubes and graphite negative active particles are mixed in a weight ratio of 1:99. Add 330.0625 mg of graphite negative particles to the carbon nanotube dispersion and stir and mix them in a magnetic stirrer. Set the rotation speed to 1000 rpm and the stirring time to 60 min to ensure uniform premixing of the carbon nanotube suspension; transfer the stirred homogeneous solution to an ultrasonic machine for intermittent ultrasonic treatment. Set the stirring speed to 600 rpm, the ultrasonic power to 210 W, and the ultrasonic time to 60 min. The ultrasonic works for 3 s and stops for 3 s.

[0065] (4) Pour the ultrasonicated solution into a suction filtration device using a porous copper current collector with a pore size of 20 μm. Maintain the vacuum degree at 0.01 MPa and suction filter until the filter paper is slightly exposed, then add deionized water for washing. Repeat 3 times. After washing, continue suction filtering for 6 h until there is no residual moisture on the surface of the filter paper.

[0066] (5) Place the obtained graphite electrode sheet in a vacuum drying oven for drying at a drying temperature of 100 °C for 12 h. After rolling, cut it to obtain a graphite negative electrode sheet with a high compaction density.

[0067] Take a pressed sheet and weigh the electrode sheet using an electronic balance to obtain the areal density of the electrode sheet. The areal density of the prepared graphite electrode sheet is 24.20 mg / cm 2 。

[0068] Application Example 2

[0069] Assemble the above graphite electrode sheet, negative lithium sheet, and separator into a 2032-type button cell.

[0070] The negative electrode uses a lithium sheet with a thickness of 500 μm. The separator model is Celgard 2400, and the material is a 25-micron microporous single-layer PP film. The electrolyte is a mixture of 1.0 M LiPF6 lithium salt and a solvent of EC:DMC:EMC = 1:1:1 Vol%, and the addition amount is 50 L. Test conditions for the cycling performance: Under the condition of 25 °C, Step 1: Leave it standing for 2 h; Step 2: Constant current discharge at a current of 0.1 C, with a cut-off voltage of 0.01 V; Step 3: Leave it standing for 2 min; Step 4: Constant current charge at 0.1 C, with a cut-off voltage of 1.5 V; Thus, cycle Steps 1 - 4 until the activation step is completed; After the activation is completed, start constant current discharge at a rate of 0.2 C to 0.01 V and charge at 0.2 C to 1.5 V, and always maintain the cycle until the battery fails or decays to less than 80% of the initial capacity.

[0071] Figure 4 It is a schematic diagram of the lithium-ion battery cycling of the high-loading electrode graphite in Example 4 of the present invention.

[0072] Comparative Example 1

[0073] Different from Example 1, the sodium vanadium phosphate positive electrode is prepared by a traditional coating method, and its preparation method includes the following steps:

[0074] The sodium vanadium phosphate material is ground for 30 min and sieved through a 200-mesh standard test sieve to obtain sodium vanadium phosphate positive electrode active particles with uniform particle size. Mix them well to prevent particle agglomeration, and place them in a vacuum drying oven for heating and drying. The drying temperature is 120 °C, and the drying time is 8 h to remove the moisture in the active particles. Weigh 1.2 g of sodium vanadium phosphate positive electrode material, 0.15 g of Ketjenblack conductive agent, and 0.15 g of polyvinylidene fluoride (PVDF) according to a mass ratio of 8:1:1. Add the sodium vanadium phosphate positive electrode material, conductive agent, and binder to N-methylpyrrolidone (NMP) solvent, and mix them evenly by magnetic stirring at a stirring speed of 1000 rpm for 3 h to form a slurry. Coat the above slurry evenly on an aluminum current collector with a coating thickness of 500 μm to form a wet film. Place the wet film in a blast drying oven at 45 °C to evaporate most of the solvent at a lower temperature, and the drying time is 12 h. Further, place it in a vacuum drying oven at 120 °C to remove the residual solvent and excess moisture at a higher temperature to ensure the combination of the electrode material and the current collector. After rolling and cutting, the sodium vanadium phosphate positive electrode material prepared by the traditional coating method is obtained. Take the sodium vanadium phosphate positive electrode sheet prepared by traditional coating and press it, and measure and weigh it with an electronic scale. The surface density of the prepared sodium vanadium phosphate positive electrode sheet in the comparative example is 8.31 mg / cm 2 .

[0075] Comparative Example 2

[0076] The difference between this comparative example and Example 1 lies in that a porous aluminum current collector with a pore size of 30 μm is used, and the remaining parameters are the same as those in Example 1; the areal density of the prepared sodium vanadium phosphate positive electrode sheet is 14.38 mg / cm 2 .

[0077] The electrode sheets obtained in Examples 1 to 4 and Comparative Examples 1 to 2 were assembled into batteries for electrochemical performance testing, and the obtained electrochemical test results are shown in Table 1:

[0078] Table 1 Electrochemical performance test results

[0079] Number <![CDATA[Charge specific capacity / mAh·g -1 > <![CDATA[Discharge specific capacity / mAh·g -1 > Example 1 106.53 105.82 Example 2 154.32 152.78 Example 3 123.41 122.07 Example 4 278.36 276.71 Comparative Example 1 92.33 91.12 Comparative Example 2 95.56 92.31

[0080] In summary, the high-loading electrode described in the present invention has a high areal loading of the electrode prepared by the suction filtration process, which is superior to the traditional coating method. The graphite electrode sheet prepared in Example 4 of the present invention is the best example, and its areal loading reaches 24.20 mg / cm 2 , and it can be known from Table 1 and Figure 4 that its electrochemical performance as an electrode material is excellent.

Claims

1. A high-load electrode, characterized in that: The invention comprises carbon nanotubes, a porous current collector and active materials, wherein the mass ratio of the active particles to the carbon nanotubes is 95:5 to 99.5:0.5; and the active materials comprise positive electrode active materials and negative electrode active materials.

2. The high-loading electrode according to claim 1, characterized in that: The porous current collector is one or more of porous aluminum foil, copper foil, polymer and composite foil thereof, and the pore size is 5 to 20 μm.

3. The high-loading electrode according to claim 1, characterized in that: The active material is one or more of lithium iron phosphate, lithium cobalt oxide, nickel-cobalt-manganese ternary, sodium vanadium phosphate, graphite, silicon-based, lithium titanate, soft carbon, hard carbon, tin-based material, and titanium-based material.

4. The high-loading electrode according to claim 1, characterized in that: The carbon nanotubes are one or more of short-range single-walled carbon nanotubes, long-range single-walled carbon nanotubes, short-range multi-walled carbon nanotubes, and long-range multi-walled carbon nanotubes.

5. A method for preparing a high-loading electrode according to claim 1, characterized in that: The following steps are involved: (1) Grinding, sieving and drying the active material to obtain uniform active particles; (2) dissolving the carbon nanotubes and the dispersant in a solvent to obtain a carbon nanotube dispersion, and then premixing the active particles in step (1) with the carbon nanotube dispersion to obtain a homogeneous solution; (3) subjecting the homogenized solution to intermittent ultrasonic stirring to obtain a mixed solution; (4) vacuum filtering and washing the mixed solution until all the material particles in the solution are adsorbed onto the porous current collector to obtain an electrode sheet; (5) The electrode sheet is vacuum dried, roll-pressed and then cut to obtain a high-load electrode sheet.

6. The method for preparing a high-loading electrode according to claim 5, characterized in that: The mass fraction of carbon nanotubes in the carbon nanotube dispersion of step (2) is 0.1-0.4wt%, the mass fraction of sodium carboxymethyl cellulose dispersant is 0.15-0.6wt%, and the remainder is solvent; the solvent is ultrapure deionized water or N-methylpyrrolidone; the mass ratio of active particles to carbon nanotubes is 95:5-99.5:0.

5.

7. The method for preparing a high-loading electrode according to claim 5, characterized in that: The drying temperature in step (1) and step (5) is 80-120° C., and the drying time is 8-12 hours.

8. The method for preparing a high-loading electrode according to claim 5, characterized in that: In the step (2), a magnetic stirrer is used for premixing, with a rotation speed of 800-1000 rpm and a stirring time of 30-60 min. In the step (3), the intermittent ultrasonic stirring treatment time is 30-60 min, the ultrasonic power is 200-300 W, and the stirring speed is 400-600 rpm.

9. The method for preparing a high-loading electrode according to claim 5, characterized in that: The vacuum degree of the vacuum filtration in step (4) reaches 0.01-0.1 MPa, and the filtration time is 3-6 hours; deionized water is added for washing 3-4 times.

10. Use of the high-loading electrode according to claim 1 in sodium ion batteries and lithium ion batteries.

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