CN-118183716-B - Preparation method of self-supporting carbon nano tube and graphene hybrid material

Abstract

The invention belongs to the field of carbon material preparation, and discloses a preparation method of a self-supporting carbon nano tube and graphene hybrid material. The preparation method comprises the steps of adding two carbon sources with different carbon contents into a mixed solution of ethanol and water to form a suspension, spraying the suspension on the surface of a metal sheet, drying, then placing the metal sheet in a high-temperature furnace, heating at a high temperature under a protective atmosphere, taking down a carbon material from the metal sheet after the high-temperature furnace is cooled, soaking the carbon material in an acid solution, washing with water, and drying to obtain the self-supporting carbon nanotube and graphene hybrid material. The method has the characteristics of simple operation, low cost, good product structure interconnectivity and easy controllable mass preparation. The self-supporting carbon nano tube and the graphene hybrid material can be used as a positive electrode carrier material of a lithium sulfur battery.

Inventors

• WANG XUEBIN
• ZHOU FANYU

Assignees

• 南京大学

Dates

Publication Date

20260512

Application Date

20240329

Claims (4)

1. 1. The preparation method of the self-supporting carbon nanotube and graphene hybrid material is characterized in that the self-supporting carbon nanotube and graphene hybrid material is a self-supporting carbon paper material, and the self-supporting carbon nanotube and graphene hybrid material is formed by crosslinking carbon nanotubes and graphene in a microcosmic manner, and is prepared according to the following steps: (1) Adding a carbon source A with low carbon content and a carbon source B with high carbon content into a mixed solution of ethanol and water, and stirring to form a suspension; (2) Placing the precursor in a high-temperature furnace, introducing protective gas, heating to a reaction temperature A, and preserving heat for a certain time; (3) Soaking a carbon material in an acid solution, and then washing and drying to obtain a self-supporting carbon nano tube and graphene hybrid material; In the step (1), the carbon source A is any one or more of melamine, dicyandiamide, urea and carbon nitride, the carbon source B is any one or more of glucose, fructose, sucrose, maltose and starch, the mass ratio of the carbon source A to the carbon source B is (10-100) 1, and the metal sheet is any one of iron sheet, cobalt sheet and nickel sheet; In the step (2), the temperature rising rate is 1-50 ℃ per minute, the reaction temperature A is 800-1400 ℃, and the heat preservation time is 0.5-6h.
2. 2. The method according to claim 1, wherein in the step (1), the drying temperature is 15 to 60 ℃ and the drying time is 1 to 60 hours.
3. 3. The method according to claim 1, wherein in the step (2), the shielding gas is any one or a combination of nitrogen, argon and helium.
4. 4. The method according to claim 1, wherein in the step (3), the acid is one of hydrochloric acid and sulfuric acid or a combination of both, the acid solution concentration is 1-12mol/L, and the soaking time is 12-72 hours.

Description

Preparation method of self-supporting carbon nano tube and graphene hybrid material Technical Field The invention belongs to the field of carbon material preparation, and particularly relates to synthesis of a self-supporting carbon nanotube and graphene hybrid material and application of the self-supporting carbon nanotube and graphene hybrid material as a positive electrode carrier of a lithium-sulfur battery. Background The graphene has larger specific surface area and higher electron mobility, and both have great potential in the energy storage field. However, both exhibit a tendency to aggregate due to van der waals forces, resulting in excellent physical properties being difficult to sufficiently achieve. By compounding the one-dimensional carbon nanotubes and the two-dimensional graphene to form a three-dimensional structure, the self-aggregation and stacking phenomena can be effectively relieved, so that the inherent physical properties of the two-dimensional carbon nanotubes and the two-dimensional graphene are maintained. Theoretical studies have also demonstrated that covalently bonded carbon nanotubes and grapheme carbon hybrid materials can extend the high electron mobility properties to three-dimensional structures. Therefore, the carbon nano tube and graphene hybrid material are used as a positive electrode carrier of a lithium-sulfur battery, and the problem of slow charge transmission in the battery reaction can be effectively solved. Currently, the preparation methods commonly adopted for carbon nanotubes and graphene hybrid materials are mainly multi-step chemical vapor deposition (nat. Commun.2012,3,1225) and self-assembly using one-dimensional carbon nanotubes and graphene oxide units (j. Mater. Chem. A2015,3,18605). The self-assembly method generally involves a plurality of process steps such as hydrothermal and freeze drying, and the bonding between the internal units of the obtained product is weak, so that the contact resistance is high. Therefore, in order to solve the problems of complex operation, high cost and insufficient product interconnectivity of the conventional method for synthesizing the carbon nanotube and graphene hybrid material, the synthesis method needs to be further optimized. Disclosure of Invention In order to overcome the defects of the prior art, the invention provides the preparation method of the self-supporting carbon nano tube and graphene hybrid material, which has the advantages of simple operation, low cost, good product structure interconnectivity and easiness in controllable macro preparation. The self-supporting carbon nano tube and graphene hybrid material can be used as a positive electrode carrier material of a lithium-sulfur battery, and the problems of insufficient actual capacity, short cycle life and the like of the lithium-sulfur battery are effectively solved. The technical scheme adopted by the invention is that the preparation method of the self-supporting carbon nano tube and graphene hybrid material comprises the following steps: (1) Adding a carbon source A with low carbon content and a carbon source B with high carbon content into a mixed solution of ethanol and water, stirring to form a suspension, spraying the suspension on the surface of a metal sheet, and drying to obtain a precursor of the metal sheet massive mixture. (2) And placing the precursor in a high-temperature furnace, introducing protective gas, heating to the reaction temperature A, preserving heat for a certain time, and taking the carbon material out of the metal sheet after the high-temperature furnace is cooled. (3) And soaking the carbon material in an acid solution, and then washing and drying the carbon material to obtain the self-supporting carbon nano tube and graphene hybrid material. In the step (1), the carbon source A is any one or more of melamine, dicyandiamide, urea and carbon nitride. Preferably, melamine and dicyandiamide are selected. More preferably, melamine is selected. In the step (1), the carbon source B is any one or more of glucose, fructose, sucrose, maltose and starch. Preferably, glucose is selected. In the step (1), the mass ratio of the carbon source A to the carbon source B is (10-100) to 1. Preferably, the mass ratio of the carbon source A to the carbon source B is selected to be 20:1. In the step (1), the metal sheet is any one of an iron sheet, a cobalt sheet and a nickel sheet. Preferably, nickel flakes are selected. In the step (1), the drying temperature is 15-60 ℃ and the time is 1-60h. Preferably, the drying temperature is set at 40 ℃ for 6 hours. In the step (2), the shielding gas is one or more of nitrogen, argon and helium. Preferably, the shielding gas is nitrogen. In the step (2), the temperature rising rate is 1-50 ℃ per minute, the reaction temperature A is 800-1400 ℃, and the heat preservation time is 0.5-6h. Preferably, the temperature rising rate is set to 10 ℃ per minute, the reaction temperature is 1000 ℃, and the heat