Preparation method of carbon nanotube aqueous slurry and application of carbon nanotube aqueous slurry in lithium battery

Abstract

The invention discloses a preparation method of carbon nanotube aqueous slurry and application of the carbon nanotube aqueous slurry in a lithium battery, and relates to the technical field of aqueous slurry. The preparation method of the aqueous slurry containing the carbon nanotubes comprises the following steps: placing a coated metal composite material and sodium hypophosphite in a reaction container, and carrying out heat treatment to obtain a coated phosphated metal composite material; adding the coated phosphated metal composite material into deionized water, and performing first intermittent dispersion; adding a dispersing agent, and stirring; carrying out second intermittent dispersion to obtain a carbon nanotube aqueous slurry; the coated metal composite material is prepared from a metal oxide graphite composite material through in-situ growth of carbon nanotubes and carbon nanofibers by a chemical vapor deposition method. The metal oxide graphite composite material is prepared from expanded stone and an organic metal compound through heat treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of aqueous slurries, and in particular to a method for preparing an aqueous carbon nanotube slurry and application thereof in lithium batteries. Background Art

[0002] With the rapid development of energy storage technology, lithium batteries have shown great application potential in new energy vehicles, smart grids and other fields due to their advantages such as high power density, fast charge and discharge, and long cycle life. However, as the core component of lithium batteries, the performance of electrode materials directly determines the overall performance of the device. Traditional electrode slurries have problems such as uneven dispersion of active materials and insufficient conductivity, resulting in low initial capacitance of supercapacitors, which makes it difficult to meet the high energy density requirements; at the same time, during long-term cycling, the electrode structure is prone to collapse and active materials fall off, resulting in a decrease in cycle capacitance retention, which greatly limits the commercialization of lithium batteries. Carbon nanotubes, with their excellent conductivity, high specific surface area and mechanical strength, have become an ideal material for improving electrode performance. However, efficiently dispersing carbon nanotubes in aqueous slurries, balancing the fluidity and stability of the slurry, and improving the initial capacitance and cycle capacitance retention of the electrode are still key technical challenges that need to be solved.

[0003] Therefore, it is of great significance to invent an aqueous slurry containing carbon nanotubes. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preparing a carbon nanotube aqueous slurry and its application in lithium batteries, so as to solve the problems raised in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions: A method for preparing an aqueous carbon nanotube slurry comprises the following steps: S1: placing a coated metal composite material and sodium hypophosphite in a reaction vessel and performing heat treatment to obtain a carbon nanotube-coated phosphated metal composite material; S2: adding the coated phosphide metal composite material to deionized water and performing a first intermittent dispersion; then adding a dispersant and stirring; performing a second intermittent dispersion to obtain an aqueous slurry of carbon nanotubes; Furthermore, the coated metal composite material is prepared by in-situ growth of carbon nanotubes and carbon nanofibers from a metal oxide graphite composite material by chemical vapor deposition; Furthermore, the metal oxide graphite composite material is prepared by heat treatment of expanded stone and organic metal compound.

[0006] Furthermore, the method for preparing the metal oxide graphite composite material comprises the following steps: placing expanded graphite and an organic metal compound in a reaction container and subjecting them to heat treatment to obtain the metal oxide graphite composite material.

[0007] Furthermore, in the preparation process of the metal oxide graphite composite material, the organic metal compound is any one of cobaltocene and ferrocene; the mass ratio of expanded graphite:organometallic compound is 0.05:0.3; and the heat treatment process includes the following steps: filling argon as a protective gas at 0°C, heating to 500-505°C at a heating rate of 2°C / min, and keeping warm for 2-2.5h.

[0008] Furthermore, the preparation method of the coated metal composite material includes the following steps: under an argon atmosphere, the metal oxide graphite composite material is placed in a reaction vessel and heated from room temperature to 500-505°C at a rate of 10°C / min, hydrogen is introduced, the temperature is raised to 750-755°C at a rate of 5°C / min, acetylene is introduced, and deposition is performed to obtain a carbon nanotube-coated metal composite material.

[0009] Furthermore, during the preparation of the coated metal composite material, during the process of introducing hydrogen, the gas flow ratio of argon:hydrogen is 60:20 sccm, during the process of introducing acetylene, the gas flow ratio of acetylene:hydrogen:argon is 3:1:1, and the total flow rate is 100 sccm; the deposition time is 5-10 min.

[0010] Furthermore, during the preparation of the coated phosphated metal composite material, the mass ratio of the coated metal composite material to sodium hypophosphite is 1:20, and the heat treatment process includes the following steps: under a nitrogen atmosphere, sodium hypophosphite is placed in the upstream area and heated to 300-305°C at a heating rate of 2°C / min, and the coated phosphated metal composite material is placed in the downstream area and heated to 500-505°C at a heating rate of 2°C / min, and the heat treatment time is 2-2.5h.

[0011] Furthermore, based on the total mass of the carbon nanotube aqueous slurry being 100%, the carbon nanotube aqueous slurry comprises 0.1-0.4% by mass of the coated phosphide metal composite material, 0.01-0.05% by mass of the dispersant, and the balance being deionized water.

[0012] Furthermore, the dispersant includes one or more of cellulose derivatives, polyvinyl pyrrolidone, polyvinyl alcohol, and cetyltrimethylammonium bromide.

[0013] Furthermore, the first intermittent dispersion and the second intermittent dispersion steps are both ultra-high-speed dispersion, the ultra-high-speed dispersion speed is 15-20Kr / min, the first intermittent dispersion and the second intermittent dispersion process, the dispersion time is 5-6 minutes, and the interval time is 1-2 minutes; the total working time of the intermittent dispersion is 20-60 minutes, and during the stirring process, the stirring speed is 600-1000r / min; and the stirring time is 15-20 minutes.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The present invention uses a step-by-step gas phase method to carry out surface engineering transformation on expanded graphite. First, metal oxides are introduced into the surface of the expanded graphite. Then, carbon nanotubes and carbon nanofibers are in-situ grown at the metal oxide sites by a vapor deposition method. The metal oxides are wrapped inside the carbon nanotubes and carbon nanofibers. Finally, the coated metal oxides are phosphated by dual-temperature zone chemical vapor deposition to prepare a carbon nanotube-coated phosphated metal composite material.

[0015] The present invention prepares carbon nanotubes through in-situ growth. First, a three-dimensional porous network structure of carbon nanotubes, carbon nanofibers and expanded graphite is constructed. The abundant mesopores and macropores of the carbon nanofibers / carbon nanotubes in the three-dimensional network are used to form through-going ion transmission channels, shortening the diffusion distance of lithium ions and accelerating the penetration of the electrolyte into the material. The high specific surface area provides more lithium ion adsorption sites, and the porous structure increases the contact area between the active material and the electrolyte, promoting the full progress of the electrochemical reaction. At the same time, the highly conductive carbon nanotubes serve as a network skeleton, forming a continuous electron transmission path with the expanded graphite matrix and the metal phosphide nanoparticles, reducing the charge transfer impedance of the electrode and greatly improving the cycle stability and capacity decay performance. Secondly, the metal phosphide nanoparticles are encapsulated inside the carbon nanotubes / carbon nanofibers. On the one hand, the agglomeration problem of the metal nanoparticles during the phosphation process can be effectively solved. On the other hand, the amorphous carbon layer on the carbon nanotube wall can limit the volume change of the metal phosphide nanoparticles during the lithiation / delithiation process, inhibiting rapid capacity decay and improving the cycle performance. DETAILED DESCRIPTION

[0016] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0017] In the following examples, the diameter of the expanded graphite is 75 μm; the remaining raw materials are commercially available.

[0018] Example 1: A method for preparing an aqueous carbon nanotube slurry, comprising the following steps: S1: placing 0.05 g of expanded graphite and 0.3 g of ferrocene in a reaction kettle, filling it with argon as a protective gas at 0°C, heating it to 500°C at a heating rate of 2°C / min, and keeping it at this temperature for 2 hours to obtain a metal oxide graphite composite material; S2: Under an argon atmosphere, the metal oxide graphite composite material was placed in a reaction vessel and heated from room temperature to 500°C at a rate of 10°C / min, hydrogen was introduced, and the temperature was raised to 750°C at a rate of 5°C / min, acetylene was introduced, and deposition was performed for 8 minutes to obtain a carbon nanotube-coated metal composite material; During the hydrogen introduction process, the gas flow ratio of argon to hydrogen was 60:20 sccm; during the acetylene introduction process, the gas flow ratio of acetylene to hydrogen to argon was 3:1:1, with a total flow rate of 100 sccm. S3: 0.05 g of a carbon nanotube-coated metal composite material and 1 g of sodium hypophosphite were placed in a dual-temperature zone chemical vapor deposition furnace. Under a nitrogen atmosphere, sodium hypophosphite was placed in the upstream zone and heated to 300°C at a heating rate of 2°C / min. The carbon nanotube-coated phosphide metal composite material was placed in the downstream zone and heated to 500°C at a heating rate of 2°C / min. The heat treatment time was 2 h to obtain a carbon nanotube-coated phosphide metal composite material. S4: adding 0.1 wt% of the carbon nanotube-coated phosphide metal composite material into deionized water and performing a first intermittent dispersion; then adding 0.03 wt% of polyvinyl alcohol and stirring; performing a second intermittent dispersion to obtain a carbon nanotube aqueous slurry.

[0019] Example 2: A method for preparing an aqueous carbon nanotube slurry, comprising the following steps: S1: placing 0.05 g of expanded graphite and 0.3 g of cobaltocene in a reaction kettle, filling the reaction kettle with argon as a protective gas at 0°C, heating the reaction kettle to 500°C at a heating rate of 2°C / min, and maintaining the temperature for 2 hours to obtain a metal oxide graphite composite material; S2: Under an argon atmosphere, the metal oxide graphite composite material was placed in a reaction vessel and heated from room temperature to 500°C at a rate of 10°C / min, hydrogen was introduced, and the temperature was raised to 750°C at a rate of 5°C / min, acetylene was introduced, and deposition was performed for 8 minutes to obtain a carbon nanotube-coated metal composite material; During the hydrogen introduction process, the gas flow ratio of argon to hydrogen was 60:20 sccm; during the acetylene introduction process, the gas flow ratio of acetylene to hydrogen to argon was 3:1:1, with a total flow rate of 100 sccm. S3: 0.05 g of a carbon nanotube-coated metal composite material and 1 g of sodium hypophosphite were placed in a dual-temperature zone chemical vapor deposition furnace. Under a nitrogen atmosphere, sodium hypophosphite was placed in the upstream zone and heated to 300°C at a heating rate of 2°C / min. The carbon nanotube-coated phosphide metal composite material was placed in the downstream zone and heated to 500°C at a heating rate of 2°C / min. The heat treatment time was 2 h to obtain a carbon nanotube-coated phosphide metal composite material. S4: adding 0.1 wt% of the carbon nanotube-coated phosphide metal composite material into deionized water and performing a first intermittent dispersion; then adding 0.03 wt% of polyvinyl alcohol and stirring; performing a second intermittent dispersion to obtain a carbon nanotube aqueous slurry.

[0020] Example 3: A method for preparing an aqueous carbon nanotube slurry, comprising the following steps: S1: placing 0.05 g of expanded graphite and 0.3 g of cobaltocene in a reaction kettle, filling the reaction kettle with argon as a protective gas at 0°C, heating the reaction kettle to 500°C at a heating rate of 2°C / min, and maintaining the temperature for 2 hours to obtain a metal oxide graphite composite material; S2: Under an argon atmosphere, the metal oxide graphite composite material was placed in a reaction vessel and heated from room temperature to 500°C at a rate of 10°C / min, hydrogen was introduced, and the temperature was raised to 750°C at a rate of 5°C / min, acetylene was introduced, and deposition was carried out for 10 minutes to obtain a carbon nanotube-coated metal composite material; During the hydrogen introduction process, the gas flow ratio of argon to hydrogen was 60:20 sccm; during the acetylene introduction process, the gas flow ratio of acetylene to hydrogen to argon was 3:1:1, with a total flow rate of 100 sccm. S3: 0.05 g of a carbon nanotube-coated metal composite material and 1 g of sodium hypophosphite were placed in a dual-temperature zone chemical vapor deposition furnace. Under a nitrogen atmosphere, sodium hypophosphite was placed in the upstream zone and heated to 300°C at a heating rate of 2°C / min. The carbon nanotube-coated phosphide metal composite material was placed in the downstream zone and heated to 500°C at a heating rate of 2°C / min. The heat treatment time was 2 h to obtain a carbon nanotube-coated phosphide metal composite material. S4: adding 0.1 wt% of the carbon nanotube-coated phosphide metal composite material into deionized water and performing a first intermittent dispersion; then adding 0.03 wt% of polyvinyl alcohol and stirring; performing a second intermittent dispersion to obtain a carbon nanotube aqueous slurry.

[0021] Example 4: A method for preparing an aqueous carbon nanotube slurry, comprising the following steps: S1: placing 0.05 g of expanded graphite and 0.3 g of cobaltocene in a reaction kettle, filling the reaction kettle with argon as a protective gas at 0°C, heating the reaction kettle to 500°C at a heating rate of 2°C / min, and maintaining the temperature for 2 hours to obtain a metal oxide graphite composite material; S2: Under an argon atmosphere, the metal oxide graphite composite material was placed in a reaction vessel and heated from room temperature to 500°C at a rate of 10°C / min, hydrogen was introduced, and the temperature was raised to 750°C at a rate of 5°C / min, acetylene was introduced, and deposition was carried out for 10 minutes to obtain a carbon nanotube-coated metal composite material; During the hydrogen introduction process, the gas flow ratio of argon to hydrogen was 60:20 sccm; during the acetylene introduction process, the gas flow ratio of acetylene to hydrogen to argon was 3:1:1, with a total flow rate of 100 sccm. S3: 0.05 g of a carbon nanotube-coated metal composite material and 1 g of sodium hypophosphite were placed in a dual-temperature zone chemical vapor deposition furnace. Under a nitrogen atmosphere, sodium hypophosphite was placed in the upstream zone and heated to 300°C at a heating rate of 2°C / min. The carbon nanotube-coated phosphide metal composite material was placed in the downstream zone and heated to 500°C at a heating rate of 2°C / min. The heat treatment time was 2 h to obtain a carbon nanotube-coated phosphide metal composite material. S4: adding 0.4 wt% of the carbon nanotube-coated phosphide metal composite material into deionized water and performing a first intermittent dispersion; then adding 0.03 wt% of polyvinyl alcohol and stirring; performing a second intermittent dispersion to obtain a carbon nanotube aqueous slurry.

[0022] Comparative Example 1: A method for preparing an aqueous carbon nanotube slurry, comprising the following steps: S1: placing 0.05 g of expanded graphite and 0.3 g of cobaltocene in a reaction kettle, filling the reaction kettle with argon as a protective gas at 0°C, heating the reaction kettle to 500°C at a heating rate of 2°C / min, and maintaining the temperature for 2 hours to obtain a metal oxide graphite composite material; S2: Under an argon atmosphere, the metal oxide graphite composite material was placed in a reaction vessel and heated from room temperature to 500°C at a rate of 10°C / min, hydrogen was introduced, and the temperature was raised to 750°C at a rate of 5°C / min, acetylene was introduced, and deposition was carried out for 15 minutes to obtain a carbon nanotube-coated metal composite material; During the hydrogen introduction process, the gas flow ratio of argon to hydrogen was 60:20 sccm; during the acetylene introduction process, the gas flow ratio of acetylene to hydrogen to argon was 3:1:1, with a total flow rate of 100 sccm. S3: 0.05 g of a carbon nanotube-coated metal composite material and 1 g of sodium hypophosphite were placed in a dual-temperature zone chemical vapor deposition furnace. Under a nitrogen atmosphere, sodium hypophosphite was placed in the upstream zone and heated to 300°C at a heating rate of 2°C / min. The carbon nanotube-coated phosphide metal composite material was placed in the downstream zone and heated to 500°C at a heating rate of 2°C / min. The heat treatment time was 2 h to obtain a carbon nanotube-coated phosphide metal composite material. S4: adding 0.1 wt% of the carbon nanotube-coated phosphide metal composite material into deionized water and performing a first intermittent dispersion; then adding 0.03 wt% of polyvinyl alcohol and stirring; performing a second intermittent dispersion to obtain a carbon nanotube aqueous slurry.

[0023] Comparative Example 2: A method for preparing an aqueous carbon nanotube slurry, comprising the following steps: S1: placing 0.05 g of expanded graphite and 0.3 g of cobaltocene in a reaction kettle, filling the reaction kettle with argon as a protective gas at 0°C, heating the reaction kettle to 500°C at a heating rate of 2°C / min, and maintaining the temperature for 2 hours to obtain a metal oxide graphite composite material; S2: Under an argon atmosphere, the metal oxide graphite composite material was placed in a reaction vessel and heated from room temperature to 500°C at a rate of 10°C / min, hydrogen was introduced, and the temperature was raised to 750°C at a rate of 5°C / min, acetylene was introduced, and deposition was performed for 5 minutes to obtain a carbon nanotube-coated metal composite material; During the hydrogen introduction process, the gas flow ratio of argon to hydrogen was 60:20 sccm; during the acetylene introduction process, the gas flow ratio of acetylene to hydrogen to argon was 3:1:1, with a total flow rate of 100 sccm. S3: 0.05 g of a carbon nanotube-coated metal composite material and 1 g of sodium hypophosphite were placed in a dual-temperature zone chemical vapor deposition furnace. Under a nitrogen atmosphere, sodium hypophosphite was placed in the upstream zone and heated to 300°C at a heating rate of 2°C / min. The carbon nanotube-coated phosphide metal composite material was placed in the downstream zone and heated to 500°C at a heating rate of 2°C / min. The heat treatment time was 2 h to obtain a carbon nanotube-coated phosphide metal composite material. S4: adding 0.1 wt% of the carbon nanotube-coated phosphide metal composite material into deionized water and performing a first intermittent dispersion; then adding 0.03 wt% of polyvinyl alcohol and stirring; performing a second intermittent dispersion to obtain a carbon nanotube aqueous slurry.

[0024] Comparative Example 3: A method for preparing an aqueous carbon nanotube slurry, comprising the following steps: S1: placing 0.05 g of expanded graphite and 0.3 g of cobaltocene in a reaction kettle, filling the reaction kettle with argon as a protective gas at 0°C, heating the reaction kettle to 500°C at a heating rate of 2°C / min, and maintaining the temperature for 2 hours to obtain a metal oxide graphite composite material; S2: Under an argon atmosphere, the metal oxide graphite composite material was placed in a reaction vessel and heated from room temperature to 500°C at a rate of 10°C / min, hydrogen was introduced, and the temperature was raised to 750°C at a rate of 5°C / min, acetylene was introduced, and deposition was performed for 8 minutes to obtain a carbon nanotube-coated metal composite material; During the hydrogen introduction process, the gas flow ratio of argon to hydrogen was 60:20 sccm; during the acetylene introduction process, the gas flow ratio of acetylene to hydrogen to argon was 3:1:1, with a total flow rate of 100 sccm. S3: adding 0.1 wt% of the carbon nanotube-coated metal composite material into deionized water and performing a first intermittent dispersion; then adding 0.03 wt% of polyvinyl alcohol and stirring; performing a second intermittent dispersion to obtain a carbon nanotube aqueous slurry.

[0025] Experiment: Electrochemical performance test: An aqueous carbon nanotube slurry, carbon black super-p, and polyvinylidene fluoride were added to N-methyl-2-pyrrolidone and stirred evenly to obtain an electrode slurry. The electrode slurry was coated on the surface of a copper foil and vacuum-dried at 70°C overnight for battery performance testing.

[0026] The mass ratio of carbon nanotube aqueous slurry, carbon black super-p and polyvinylidene fluoride is 8:1:1.

[0027] The electrolyte was prepared by dissolving 1 M lithium bis(fluorosulfonyl)imide in ethylene carbonate and diethyl carbonate in a volume ratio of 1:1.

[0028] The experimental results are shown in Table 1 below.

[0029] Table 1 Electrochemical performance test data

[0030] Conclusion: The aqueous slurry containing carbon nanotubes prepared by the present invention has excellent electrochemical properties. Compared with cobaltocene, ferrocene has a smaller reversible capacity but a higher capacity retention rate.

[0031] In Comparative Example 1, the deposition time is too long, resulting in excessive growth of carbon nanofibers, increased length and entanglement with each other, and deposition of amorphous carbon on the surface, which leads to a decrease in pore size, coverage of active sites of metal phosphide nanoparticles, decreased structural stability during the cycle, and decreased electrochemical performance.

[0032] In Comparative Example 2, the deposition time is too short, resulting in a large amount of carbon nanotubes growing, a small proportion of carbon nanofibers and being shorter, and the carbon nanotubes are easily agglomerated, resulting in the exposure of metal phosphide nanoparticles, a decrease in structural stability during the cycle, and a decrease in electrochemical performance.

[0033] In Comparative Example 3, no phosphating operation was performed, a continuous electron transmission path could not be formed, and the charge transfer impedance of the electrode could not be reduced, resulting in reduced cycle stability and capacity decay performance.

[0034] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

Claims

1. A method for preparing an aqueous carbon nanotube slurry, characterized by: The following steps are involved: S1: placing a coated metal composite material and sodium hypophosphite in a reaction vessel and performing heat treatment to obtain a coated phosphated metal composite material; S2: adding the coated phosphide metal composite material into deionized water and performing a first intermittent dispersion; then adding a dispersant and stirring; performing a second intermittent dispersion to obtain an aqueous slurry of carbon nanotubes; The coated metal composite material is prepared by in-situ growth of carbon nanotubes and carbon nanofibers from a metal oxide graphite composite material through a chemical vapor deposition method; The metal oxide graphite composite material is prepared from expanded stone and an organic metal compound through heat treatment.

2. The method for preparing an aqueous carbon nanotube slurry according to claim 1, wherein: The preparation method of the metal oxide graphite composite material comprises the following steps: placing expanded graphite and an organic metal compound in a reaction container, and performing heat treatment to obtain the metal oxide graphite composite material.

3. The method for preparing an aqueous carbon nanotube slurry according to claim 2, wherein: In the preparation process of the metal oxide graphite composite material, the organometallic compound is any one of cobaltocene and ferrocene; The mass ratio of expanded graphite to organometallic compound is 0.05:0.

3. The heat treatment process comprises the following steps: filling argon as a protective gas at 0°C, heating to 500-505°C at a heating rate of 2°C / min, and keeping the temperature for 2-2.5 hours.

4. The method for preparing an aqueous carbon nanotube slurry according to claim 1, wherein: The preparation method of the coated metal composite material comprises the following steps: placing a metal oxide graphite composite material in a reaction vessel under an argon atmosphere, heating the temperature from room temperature to 500-505°C at a rate of 10°C / min, introducing hydrogen, heating the temperature to 750-755°C at a rate of 5°C / min, introducing acetylene, and depositing the metal composite material to obtain the coated metal composite material.

5. The method for preparing an aqueous carbon nanotube slurry according to claim 4, wherein: During the preparation of the coated metal composite material, during the process of introducing hydrogen, the gas flow ratio of argon:hydrogen is 60:20 sccm, during the process of introducing acetylene, the gas flow ratio of acetylene:hydrogen:argon is 3:1:1, and the total flow rate is 100 sccm; the deposition time is 5-10 minutes.

6. The method for preparing an aqueous carbon nanotube slurry according to claim 1, wherein: During the preparation of the coated phosphated metal composite material, the mass ratio of the coated metal composite material to sodium hypophosphite is 1:

20. The heat treatment process includes the following steps: under a nitrogen atmosphere, sodium hypophosphite is placed in the upstream area and heated to 300-305°C at a heating rate of 2°C / min; the coated phosphated metal composite material is placed in the downstream area and heated to 500-505°C at a heating rate of 2°C / min; the heat treatment time is 2-2.5 hours.

7. The method for preparing an aqueous carbon nanotube slurry according to claim 1, wherein: Taking the total mass of the carbon nanotube aqueous slurry as 100%, the carbon nanotube aqueous slurry comprises 0.1-0.4% by mass of the coated phosphide metal composite material, 0.01-0.05% by mass of the dispersant, and the balance being deionized water.

8. The method for preparing an aqueous carbon nanotube slurry according to claim 1, wherein: The dispersant includes one or more of cellulose derivatives, polyvinyl pyrrolidone, polyvinyl alcohol, and cetyltrimethylammonium bromide.

9. The method for preparing an aqueous carbon nanotube slurry according to claim 1, wherein: The first intermittent dispersion and the second intermittent dispersion steps are both ultra-high-speed dispersion, the ultra-high-speed dispersion rotation speed is 15-20Kr / min, the dispersion time is 5-6 minutes and the interval time is 1-2 minutes during the first intermittent dispersion and the second intermittent dispersion process; the total working time of the intermittent dispersion is 20-60 minutes, and during the stirring process, the stirring speed is 600-1000r / min; and the stirring time is 15-20 minutes.

10. Application of the carbon nanotube aqueous slurry prepared by the method for preparing a carbon nanotube aqueous slurry according to any one of claims 1 to 9 in lithium batteries.

Images