Graphene carbon nanotube composite material, preparation method and application thereof

Abstract

The invention relates to a supercapacitor electrode material. The material is formed by mixing graphene and carbon nanotubes according to a mass ratio of 3: 1. The graphene is prepared by an electrochemical stripping method, the carbon nanotubes are prepared by an arc discharge method, and when 1M NaCl is used as an electrolyte and a test is carried out at a scanning rate of 10mV / s, the specific capacitance of the composite material can reach 179F / g.

Description

Technical Field

[0001] The invention relates to the preparation and application of supercapacitor electrode materials, in particular to a method for enhancing the capacitance of supercapacitor electrodes by using a graphene and carbon nanotube composite material and the application thereof. Background Art

[0002] As the demand for energy storage increases, supercapacitors have attracted widespread attention due to their high power density, long cycle life, and fast charge and discharge capabilities. Traditional supercapacitor electrode materials have problems such as low energy density and high cost. Therefore, the development of a new, high-performance, low-cost supercapacitor electrode material has become a hot topic in current research. Summary of the invention

[0003] The present invention provides a novel supercapacitor electrode material, which is prepared by mixing graphene and carbon nanotubes in a mass ratio of 3:1. The graphene is prepared by an electrochemical stripping method, and the carbon nanotubes are prepared by an arc discharge method. When 1M NaCl is used as an electrolyte and tested at a scan rate of 10mV / s, the specific capacitance of the composite material can reach 179F / g.

[0004] The present invention also provides a method for preparing the above-mentioned supercapacitor electrode material, including electrochemical exfoliation of graphene, arc discharge preparation of carbon nanotubes and mixing the two.

[0005] The present invention also provides a method for preparing a supercapacitor electrode material, comprising the following steps: a) preparing graphene by an electrochemical exfoliation method; b) preparing carbon nanotubes by an arc discharge method; and c) mixing the graphene and the carbon nanotubes in a mass ratio of 3:1.

[0006] As a further improvement of the above method, the electrochemical stripping process in step a) uses H2SO4 ion solution as electrolyte and is carried out under DC bias.

[0007] As a further improvement of the above method, the arc discharge process in step b) is carried out in distilled water to prepare carbon nanotubes.

[0008] The present invention also relates to the application of the supercapacitor electrode material in a supercapacitor.

[0009] The supercapacitor comprises the supercapacitor electrode material according to the above method, wherein the electrode material is applied to at least one electrode.

[0010] As a further improvement of the above method, the electrode of the supercapacitor is combined with the electrode substrate by using polyurethane as an adhesive to fix the graphene and carbon nanotube composite material.

[0011] As a further improvement of the above method, for the preparation of graphene and carbon nanotubes, the preparation of graphene adopts an electrochemical stripping method. Specifically, a graphite rod is used as an anode, a platinum wire is used as a cathode, and an H2SO4 solution is used as an electrolyte, and electrochemical stripping is performed under a DC bias to obtain graphene.

[0012] For the preparation of carbon nanotubes, the arc discharge method should be used. In a distilled water environment, two graphite electrodes are used to generate an arc to prepare carbon nanotubes.

[0013] As a further description of the method steps, the preparation process of the graphene / carbon nanotube composite material is as follows: the prepared graphene and carbon nanotubes are mixed in a mass ratio of 3:1, and ultrasonic treatment is used to ensure sufficient mixing, thereby obtaining the graphene / carbon nanotube composite material.

[0014] As a preparation step of the supercapacitor electrode, polyurethane should be used as an adhesive, the graphene / carbon nanotube composite material should be coated on the electrode substrate, and the supercapacitor electrode should be obtained after drying.

[0015] The electrochemical performance test steps of the product are as follows: 1M NaCl solution is used as the electrolyte, and the electrochemical performance of the electrode is evaluated by cyclic voltammetry (CV) and constant current charge and discharge test (GCD). The test results show that the electrode material of the present invention exhibits excellent specific capacitance, good cycle stability and fast charge and discharge capability.

[0016] The supercapacitor electrode material of the present invention can be widely used in various devices requiring fast charging and discharging and high reliability, including but not limited to load cranes, electric forklifts, electric vehicles, portable electronic devices and any occasion requiring a high-performance energy storage system. Beneficial Effects

[0017] The electrode material of the present invention exhibits a specific capacitance of up to 179 F / g, which is significantly higher than many traditional electrode materials. Graphene and carbon nanotubes are prepared by electrochemical stripping and arc discharge methods, which are relatively simple and low-cost. And the materials and methods described are suitable for large-scale production. Example

[0018] In order to further illustrate the present invention, a specific implementation of the scheme is provided below, but the present invention is not limited to this embodiment.

[0019] Example 1: Preparation and testing of graphene / carbon nanotube composite materials 1) Graphene was prepared from graphite rods using electrochemical exfoliation.

[0020] 2) Preparation of carbon nanotubes by arc discharge method.

[0021] 3) Graphene and carbon nanotubes were mixed in a mass ratio of 3:1 and ultrasonic treatment was used to ensure uniform mixing.

[0022] 4) Using polyurethane as an adhesive, the graphene / carbon nanotube composite material is uniformly coated on a stainless steel substrate to form an electrode, and then dried in an oven at 80°C.

[0023] 5) The prepared electrode was installed in a supercapacitor test device, and the electrochemical performance was tested using 1 M NaCl solution as the electrolyte.

[0024] 6) Cyclic voltammetry (CV) tests were performed at a scan rate of 10 mV / s. The results showed that the composite material electrode exhibited a nearly ideal rectangular CV curve, indicating excellent capacitive performance.

[0025] 7) The specific capacitance, energy density and power density of the electrode were evaluated by constant current charge and discharge (GCD) test. The test results show that the specific capacitance of the graphene / carbon nanotube composite electrode reaches 179F / g, and the energy density and power density are better than those of traditional electrode materials.

[0026] 8) A long-term cycle stability test was carried out. After 10,000 charge and discharge cycles, the electrode maintained a high specific capacitance retention rate, proving its excellent cycle stability. Industrial Applicability

[0027] The graphene / carbon nanotube composite material electrode of the present invention has broad industrial application prospects in the field of supercapacitors, including but not limited to: electric vehicles, renewable energy storage, portable electronic devices, etc.

Claims

1. A supercapacitor electrode material, characterized in that: The material is made of graphene and carbon nanotubes mixed in a mass ratio of 3:

1.

2. The supercapacitor electrode material according to claim 1, wherein the graphene is prepared by an electrochemical exfoliation method, and the carbon nanotubes are prepared by an arc discharge method.

3. The supercapacitor electrode material according to claim 1 or 2, when 1M NaCl is used as the electrolyte and tested at a scan rate of 10mV / s, the specific capacitance of the material can reach 179F / g.

4. A method for preparing a supercapacitor electrode material, comprising the following steps: a) preparing graphene by electrochemical exfoliation; b) preparing carbon nanotubes by arc discharge; c) mixing the graphene and carbon nanotubes in a mass ratio of 3:

1.

5. The method according to claim 4, wherein the electrochemical stripping process in step a) uses H2SO4 ion solution as electrolyte and is performed under DC bias.

6. The method according to claim 4 or 5, wherein the arc discharge process in step b) is carried out in distilled water to prepare carbon nanotubes.

7. A supercapacitor, characterized in that: The supercapacitor comprises the supercapacitor electrode material according to claim 1, wherein the electrode material is applied to at least one electrode.

8. The supercapacitor according to claim 7, wherein an electrode of the supercapacitor is bonded to an electrode substrate by using polyurethane as a binder to fix the graphene and carbon nanotube composite material.